I'm actually going to say yes (though not more prevalent than 'transphobia' ), BUT in my experience it has actually been homosexual people who have usually had the problem with my bisexuality. I have had so many comments from gay men who have tried to tell me that bisexuality isn't real, that 'it's a stepping stone', that I'm 'basically half gay' etc. and it's usually heterosexual people who don't have a problem with it.
It is honestly pathetic when I see gay men trying to tell me that my sexuality isn't a thing as if they somehow have no idea what it's like to be a minority sexuality.
I'm not one who goes around campaining for more bisexual people in the media and chanting at gay pride and **** cause I'm not about that, but I think some gay men really need to get it into their minds that sexuality is not just 'okay you're either straight or converting towards homosexuality', because the fact they think that way is laughably ironic.