Unfortunately the answer is probably not, but maybe? You rightly point out that the Ptolemaic dynasty was Macedonian in origin, and their drinking habits had not changed much by the 1st Century BCE.

While beer was still widely produced and consumed by the populace, the Ptolemaic dynasty and the Greek settlers who moved to the country during that period had worked to build a reasonably large wine industry. Egyptian wine was not held in high regard by outsiders, but some of the better varieties did earn some praise. If Roman sources are to be believed, than Cleopatra served copious amounts of wine, and many varieties, when she hosted dinners or held court. During Julius Caesar's stay in Egypt, this is likely what he would have found available.

In fact, the feasting culture of the Ptolemaic dynasty reflected very Macedonian tastes, albeit augmented by spices, art and luxuries from Asia and Africa. There's precious little mention of beer in accounts of Ptolemaic royal dining, which could merely mean that a cheap staple like beer was below mention, like bread or porridge, but still consumed.

He did take a brief tour of the country following the Alexandrian War, but was entertained by Cleopatra's (evidently quite mobile) court. Moreover, when Ptolemaic nobles went on tour they were hosted by local elites such as Egyptian priests and local governors who were well equipped to host guests in the Hellenistic fashion the dynasty preferred. They were also already accustomed to high status Roman visitors and their tastes.

It is still possible that Julius Caesar might have been offered beer at some point during his trip, if only as a novelty, but those entertaining him might been more eager to impress by demonstrating "more cultured" (i.e. Greek) tastes. We will probably never know.

Edit: a word