Among the people I am "out" to, I have only experienced mild discrimination from a gay male friend, who called me things like butch (even though I consider myself fairly feminine) somewhat jokingly but it was also hurtful.
Among people I am not out to, I have been discriminated against just for supporting same-sex marriage (so that doesn't encourage me to come out 100% ). That comes from heterosexual people. I have heard people who didn't know I am bisexual talking about how bisexuality isn't real, it's just for attention etc. That comes from heterosexuals and homosexuals alike. Whether they are straight or gay, they still only understand being attracted to a single gender, so I feel like they are equally likely to not understand bisexuality.