I don't know if it can be done with a U.S. address, but you could apply for the Platinum International Dollar Charge Card via AmEx UK for $550 annual fee. This includes the top level Priority Pass for two people -- the card holder and a supplementary platinum card hold (no charge above the $550 for a supplementary card holder).

I believe you would have to have a non-U.S. address to apply for and receive the card initially, but my understanding is that you can change the address to a U.S. address any point after you have the card. YMMV.

Susan