I don't really see how the bread/wine bit relates at all to the topic; but if you simply are going by the biblical narrative, in the book of Acts there are numerous discussions about Paul's primary goal being to teach Christianity to the non-Jews (Gentiles); and Paul himself speaks regularly that his ministry was to the Gentiles (Ephesians chapter 3, for one reference)

While there is no way to say what Christianity would or would not have become without Paul, both Catholics & protestants agree that the spreading of Christianity outside of Judaism was largely due to Paul (along with the help of a few others that worked with him, Barnabas, Silas, & Timothy come to mind).

While I can't find the exact reference right now, tradition holds that Peter was in charge of the church in Jerusalem (and therefor the growth of Christianity in Israel among the Jews), and Paul was in charge of spreading Christianity to the rest of the Roman empire (which is why most of the New Testiment is letters Paul wrote to the various churches he founded in Ephesus, Corinth, Rome, etc)

There were other missionaries to the gentiles. It might be difficult to unravel their interactions with Paul in the Roman empire to say how successful they would have been, so you might consider Thomas as a clearer example as he appears. He went east into Parthia and modern-day Pakistan (and according to the St Thomas Christians of Kerala in SW India, also founded their churches, though I gather the Roman church disputes this). I'm using him as an example as his area of mission did not overlap with Paul's. The St Thomas Christians ended up being in the Syrian Orthodox church, which suggest that they message they were given was not radically at odds with mainstream Christianity in the Levant.

Within the Roman empire, Paul and "Luke" (i.e. the author of Luke/Acts) mention several competing or coöperating missionaries. Their letters are not preserved within the canon of the New Testament except where they were mistakenly assumed to be written by Paul, and as such the ones which were included share many Pauline views. Competing missionaries are mentioned in several of Paul's letters, but particularly in Galatians where they are trying to put more emphasis on the importance of Jewish law in Christian life - bear in mind that these were not separate religions at this time.

So in summary - Paul was important and certainly shaped the content of the NT. However it doesn't appear that the basic message of the NT was uniquely Pauline.

i can give you the biblical perspective. To be clear, Christianity had already existed before Paul in the book of Acts when Peter called the 120 disciples together on the Day of Pentecost, who were then scattered in the first instance of the gospel. Paul was most certainly not the creator of Christianity as the record of his first appearance was of a devout and zealous Jewish Pharisee who persecuted Christians. His first significant record in the Bible was of his overseeing of the stoning of Stephen the martyr; then secondly when he obtained the equivalent of a warrant from the Jewish authorities to arrest "those who called on the name of Christ". So he couldn't have been the first Christian.

Secondly, Christianity was arguably at the time the biggest opponent to the Jewish religion. One needs to make the historical distinction that Christianity and Judaism are completely separate and distinct religions. Judaism began in the Old Testament Torah with the writings of Moses, which culminates in the prophecy of Isaiah the prophet of a Messiah who would return at the end of days. Christianity argues that Jesus is this Messiah, which is why his birth and death is the bridge between the Old and New Testaments; Judaism argues that the Messiah has not arrived and Jesus was just one prophet out of many. So even before Paul was of age, Christianity could not have been an extension of Judaism. Some would argue that it started in earnest with Peter, which is why the Catholic Church recognizes him as the first pope in technicality - and it was only after some ten odd years that Paul would enter the spotlight.

However, it is indeed true that Paul's ministry was the catalyst which revitalized Christianity and made it what we know today; such is the recognition of his authority that his letters make up over half of the New Testament. Would Christianity have remained a tiny sect if it weren't for Paul? Well, that's like asking whether America would have been founded if Columbus was never born. It's hard to imagine except if you apply a parallel universe theory.

It is a strong argument.

The first followers of Jesus were Jews. As Jews they expected other followers to observe Judaic laws, such as those related to diet and circumcision.

Circumcision was seen as abhorrent in contemporary Roman society. It is clear from several Biblical texts that Paul was the key figure arguing that male followers of Jesus should not be required to be circumcised.

The circumcision controversy was crucial in allowing Christianity to expand into wider Roman society.

Sources: White, "From Jesus To Christ"; https://en.m.wikipedia.org/wiki/Council_of_Jerusalem