i never thought about it but it's true that julia was never seen at the 'blue whale'(other than the scene mentioned here that i haven't actually seen).
some characters seemed to live there.burke,sam,joe,roger,jason and willie certainly frequented the place.
even "good girls" like vicki,carolyn and maggie seemed to be always up for a drink and a spin on the dance floor.
in general the supernatural characters didn't seem to have much of a fondness for the place but i can recall a few episodes where barnabas and nicholas drop in for a drink.i always think for some reason they are out of place there.