Thanks Lou, interesting. Reciprocity can be quite iffy. We've belonged to several Bay Area clubs that are affiliated with PICYA (Pacific Inter Club Yachting Association). When we took a cruise down the coast, we found that most Southern California YCs don't recognize PICYA; They have their own S Ca equivalent association, which we hadn't heard of. So, no reciprocity for us, although they let us berth (for a price) and enter their clubhouses.
Coincidentally, Chris was Commodore of one of the clubs when we applied for, and were accepted into, PICYA. Had a nice 'initiation' ceremony at the Tahoe YC (on North Shore).
Can't speak for the rest of the country, but I have heard of some folks in PICYA affiliated clubs being welcomed at a YC in Hawaii..