Marriage equality is about giving homosexuals the same rights as heterosexuals to have a "state-endorsed" marriage, i.e. a marriage accepted by society as a whole, rather than a religious marriage.
Society currently endorses the right for a man and woman who love each other to make a lifelong commitment to each other through marriage.
Our society does not endorse bigamy, bestiality or paedophilia, and therefore does not endorse marriage on that basis. This makes the idea of a man marrying his pet, for example, irrelevant to the discussion.
But our society DOES say it's OK to be homosexual, and therefore it should endorse marriage on that basis, allowing two homosexuals who love each other to make a lifelong commitment to each other through marriage.
It's nothing to do with religion - religions can allow their own versions of marriage, or not. It's everything to do with society, and society endorsing lifestyles that a majority within society believes are acceptable.
Bigotry is not a good choice of word in this scenario, because it's very much a black and white issue to anyone with a strong conviction, and this is an issue where it's worth having a strong conviction. Therefore everybody who has a strong conviction, one way or the other, is in a way bigoted against the opposite side. It's just the wrong word. Whichever way this bill goes, for the "losing" side to believe that the "winning" side was bigoted against them is just wrong.
I think, however, that those of a religious persuasion and who are opposed to marriage equality, sometimes seem to have mixed up their religion and its version of marriage with society as a whole and its version of marriage.
What this really comes down to is "Does society accept homosexuals?" If so, society needs to accept homosexual marriage, and endorse the idea of two homosexuals expressing a lifelong commitment to each other.