I feel you. You found a place that was part of your GAL and you're connected to the location as a place that's special to you. But if you're noticing this bartender is acting kind of "on the edge" of appropriate than yes, your W is DEFINITELY noticing. (I think most of us are a bit thick when it comes to being flirted with. So if you see it, it's likely overt :))
I think the best thing is for now to work on finding a new hang-out. This is out of not just love for your W, but also respect. You respect that even though she didn't ask you to stop going, you understand she's uncomfortable. Perhaps on rare occasion you could visit that bar if W is with you. But only if she is accompanying you and is up for it.
What if you engage W in helping you to find a new hangout? Go test drive a bunch together, chat about the pros and cons of different watering holes. Perhaps you can find a new place that suits the two of you.
Also, unless the bartender is an owner - bartending tends to be a profession with high turnover. So who knows, perhaps this bartender will be gone in 3 months to the next adventure. You may have your bar back in the future.
