So with this club where Planetouched from across the planes meet, who's the staff and who's the elite? Would it be something where lowly initiates get tasked with being housekeepers and some menial jobs, or is it a bunch of hired outside help, or something magical like Unseen Servants and Homunculi?
If it's more of a secret society, I guess it would be the type that dresses in robes and has rituals and the like. But if it's just a social club then it's a bunch of Planetouched coming back with trophies from their journeys across the planes.