Have you checked to see whether you can add your wife to your account and get her a President's Club card in her name?
I've got President's Club via AmEx Centurion, and when I activated the PC membership, I was automatically given a card for my husband with his name on it.
This came in handy once when we missed a connecting flight, and had to split up on flights a few hours apart. He arrived at our destination first and was able to go to Avis and pick up the rental car by shifting it to his name and showing his PC card, and all other terms (including our 2-class upgrade) remained the same.
Susan