I would check into that... when a landowner leases property, they do confer rights and priveledges with it... just like me and my rental property... i'm not the landowner, but i have the right to eject someone from "my property". i forget the mumbo jumbo on it but basically for the term of the time i have paid for, i have bough limited rights to the property... the landowner can restrict what i can and cannot do(such as renovations and whatnot) but i have final say on who can enter my residence... even the landlord cannot enter my home without my permission unless they give me very specific notification. if they walk up and ask to enter... if they haven't given me 24 hours (the law here at least) then i can refuse them access to my home... even if they suspect that i've been committing illegal acts.
so if a bar "owner" is renting the space... they do have the right to eject you for no stated reason at all... The law states that they have the right to refuse service to anyone... the law also allows for you to sue them if they have ejected you and violated your basic human rights...
so, essentially, if a bar owner was a homophobe and decided they didn't want you on the property because you are gay they can legally eject you citing their right to refuse service to anyone for any reason and give 'no reason" and sadly the law applies... however, you can sue them for doing so on the basis of sexual orientation and you would win in court if you can show that the only reason was because you were gay, but if the police are called to enforce it because you refused, the police will still have to remove you from the property, even if they disagreed with it...
i've seen it done... the law is touchy... but they still can do it, even if they'll loose in the long run...