The Johathan Club in downtown Los Angeles is a long-time "luncheon club" where downtown business executives & professionals have memberships.
Similar to a country club, but without the golf course, etc. I think there was a gym facility there too. (I've been there a few times as a guest, but many years ago).

They also had a beach club "satellite" location in St. Monica with umbrellas, etc. Still operating, I think -- for members only.

I was not aware of the hotel (in the picture) being associated with Johathan Club, but my knowledge doesn't go back that far.

I assumed the "JC" chips went with the downtown LA location, though they could have traveled to the St. Monica hotel location too.