There's a book (The Secret Emotional Life of Zhou Enlai) making that case, but there's no conclusive evidence.

It's also questionable whether he would've viewed homosexuality in our modern terms as an identity/orientation rather than the older view that mainly focused on the physical acts; homosexuality being something you did rather than being something you were. I.e. it could be the case that he he felt sexual attraction to men, never acted on it, and therefore did not regard himself as homosexual. So it's hard to even define the question well, much less answer it conclusively.