I don't believe its explicitly stated anywhere in the story that the "regulars" are supernatural. Scattercat used the term "mystery cult" which implies cultists, but not necessarily supernatural (or supernaturally empowered) ones. I mean, they wear loafers and sneakers, etc....
I thought it was an interesting meditation on co-dependency and addiction linked in a number of interlocking societal forms (cigarettes, alcohol, marriage, drugs, murder).
Oh, and I liked the drug dealer's voice - sounded like Jonathan Richman with a cold....