"Dark pattern" is specific to digital user interfaces, the bartender use case might be just called emotional marketing or, more plainly, flattery.

Keep in mind, digital or not, not all forms of negatively viewed tactics hold the same weight. E.g. a nagging confirmation for cancellation is typically viewed less negatively than confirm shaming, even though both are often listed as types of dark patterns. The type of coercion in the bartender example is likely towards the less negative side of manipulative tactics in most people's minds.

Just half-serious here when musing: not in any practical sense, but philosophically perhaps. The bartender is in the Hospitality business, and assuming that the essence of that business is genuine hospitality, there is no dark pattern if the compliment and wink are genuine. But if they are just a marketing gimmick that the bartender pulls at every table like a used cars salesman, then it is a deception pattern.

If he talked the whole time about making a mojito, then gave you a water

If you're sitting at the bar, you're likely waiting to be served anyway. It might get the bartender a bigger tip, which is a transaction I'm okay with.

Dimly lit