I'm not a mental health expert.
But I'd guess that probably, yeah, you had real attraction to men. For one thing, there are tons of bi people out there (even though nearly all the men are closeted). It's probably more common than being left-handed. But also, if you didn't have some potential to be attracted to men, then it seems strange that your bipolar episode would latch onto that.
But like I said, I'm not an expert.