I always liked this idea and wish the https://www.atlantacoworking.club/ or similar clubs, collectives, or co-ops would do something similar (instead of it being run by any individual coworking space).
Yeah, follow the Priority Pass/Golf Course Networks/Gym Franchise model.
Pay a little more locally for the ability to Roam in the network.
Deskpass.com lets you drop into any coworking space in their network. It looks like they are up to 11 cities. You pay a subscription and then the coworking spaces get a flat fee for the day when you actually show up to their space.