Short answer is no, he was viewed as the head of the Roman Church of course but beyond that he didn’t have very much more authority than the bishop of, say, Antioch. In fact, the bishop of Rome at the time, Pope Sylvester I, did not even attend the Council. Likely a strategic move on his part, since the council served more as a political apparatus to strengthen Constantine’s dominion over the church. That being the case, Constantine had much greater authority than any of the bishops in attendance. It wasn’t until Jerome’s or even Augustine’s time that the papacy took on a more dominant role in church affairs, with Pope Damasus claiming precedence over the other bishoprics by virtue of Rome’s link to Peter as its original founder. This school of thought, known as apostolic succession, allowed Roman popes to declare their superiority over the teachings and customs of the other bishoprics through their link to Peter. Once the Roman government collapsed, the papacy took on an even greater role as the last vestige of Roman political leadership, with Popes Leo and Gregory (both ‘The Great’, the only two popes to earn such title) having extensive dealings and negotiations with the Gothic tribes. This rigidly secured the primacy of the Roman Church well into the Middle Ages. For further readings on the early church in general I highly recommend Peter Brown, he’s a fantastic scholar and perhaps (quite surprisingly, for a historian) an even better author.