What are some example of memberships/licenses that unlock access to a 3rd party? 
Credit card->Airport Lounge
AARP->Discounts
Health Insurance->Network
Student/Military ID->Discounts

CA library card -> free or discounted museums (https://discoverandgo.org/)
Museum Membership -> free reciprocal access (https://www.astc.org/)

Lots more like the above (https://narmassociation.org/, https://findachildrensmuseum.org/reciprocal-network/, etc)

Zero-to-one builder in SF 🇨🇦🇺🇸

I've used the AAA hotel discounts numerous times.