Bar logos come in all kinds of shapes and styles. They can range anywhere from a shield logo with a retro look, to a modern-looking wordmark. While this means that you can be creative when designing a logo for a bar, you'll have to keep some things in mind. Every existing bar has its unique character that its new logo will have to reflect to be a perfect fit with the bar and its target audience.
A lot of bars have been around for ages and their owners often want that to be reflected in the logo. These more retro-looking logos mostly take inspiration from the old logos of the bar itself as it helps with staying recognizable and authentic.
If a bar wants to be seen as new and fresh, it may go for a more modern-looking logo. This will make the bar look a lot more current but it can also quickly go out of style which is a big downside of these kinds of logos.