Thank you, Chrissie and Lee, both for your thoughts on the topic of this thread and for your efforts to stop this thread going into other directions.
IMHO, I believe that the first bartender was maybe 70% being derogatory/insulting towards Jack, perhaps because he'd heard of the results of the day or perhaps because he didn't agree with one man buying a beer for another or perhaps because he knew Jimbo better than Jack did, I don't know, and 30% trying to be friendly, giving Jack possibly an alternate suggestion that he hadn't considered. I believe that the second-night bartender, as one of you said, was much more friendly towards Jack simply because Jack was then asking about a beautiful girl, instead of chatting up a rodeo clown man. I think Mr. Lee changed bartenders specifically, even though bartenders in a small town would generally stay the same from one night to the next, so that we could see the dichotomy of each of these men's pieces of advice and information towards Jack. Do we know for sure if either of those bartenders had an opinion about homosexuality? No, we don't. All we do get to see is one of those bartenders maybe sort of semi-sneering at him, and one of those bartenders goading/enticing him along, as he can see Lureen is already well on her way to making her move. Perhaps that's the only lesson we're meant to learn from those particular two scenes, is that every person has a different background and basis of knowledge, and some people feel the need to inflict it upon others, with or without their consent.
I truly believe that Jimbo picked up on Jack's half-hearted attempt at flirting, and was scared from it, and walked away. And I think that Jack, after having lost that day so badly, accepted it. And I think that, after having won on the second day, he walked back in there cocks-a-blazing, ready to stand up to anyone who looked at him funny. And God love him for having that bravery in his soul. Not many people would have, would they, after being humiliated so badly just a night before? Doesn't really matter to me whether his relationship with Lureen turned out successful or not. Least he had the balls to step up to the plate.