I don’t need to know why you don’t want to interact with this bartender and I understand why you don’t want to switch bars for him. That would mean letting him win! All I need to know is, how are his drinks? If they’re no biggie, call for beer from the other tenders or smuggle in a flask. In the case that his martini is to die for, just send a friend over to get it for you; that will prevent him from spitting in it., too (Side note: if he was to die for, you should let your friend get at him, as a thank you.)
When and if you are forced to order from him, use cognitive behavioral tricks to teach him not to talk to you. Tip him more when he avoids eye contact and growl at him when he asks what you’re doing later, etc. Either way, he’s stuck behind the bar and you aren’t. As long as you leave before last call, you’ll be fine! Before you screw the next hand that serves you, keep this in mind.