I saw that Jungle Club. Charles Perrone ran it. He was one of those no-nonsense characters who filed a complaint against the police for disrupting his business with all their raids against his illegal gambling!
I think Rost was probably doing his own thing. He had the Palace Club at 239 Second St in the early 1930s (ordered chips marked "PLOC PLC" which I've never seen) before moving to 107 Hawkins Ave around 1935.
I think Rankin was probably big enough for a couple places, but you never know. These guys have some weird connections.