However, Priority Pass has also added restaurants, and memberships sponsored by American Express are not valid at those locations. The restaurant knows this, and may ask if who sponsors yours. In this regard, a membership sponsored by American Express is inferior to those offered by other banks.
Do we know yet if those restaurants can even scan an Amex-issued PP card now? Seems different than lounges that swipe the card and input number of guests. This would be a specific bill amount.