I can't come up with a logical guess of where the MB / Joker Club chips might have been used in Suisun City. Those chips have long been attributed to the city of Martinez. The Staeffler guide attributed it to a place called the Mountain Bar. It sounds like that attribution may be wrong. I tried to research those chips a while back and could not find evidence that a place called the Mountain Bar or Joker Club even existed in Martinez.

What did you figure out?