I think it could be possible seeing as that group wouldn’t have cared and also that they say that having a partner who’s name rhymes is weird I one of the missions and an example is bill and will or something

No, Bill is not stated or implied to be homosexual. Quite the opposite, in fact, as he’s said to be jealous with John as he was the one who ended up with the romantic partner Bill desired: Abigail.

I’ve heard people try and claim that Bill is homosexual before, saying, for example, that the fact he was remorseful of Kieran is proof that he’s gay. That’s nothing more than unsubstantiated speculation.

I think it's subtly hinted throughout the game, or at least bisexual/curious

No, Hosea saying bill and Phil won't work romantically is simply a joke.