Wandering Aramean reports that American Express and US Airways have struck a lounge access deal — Platinum (and Centurion) cardholders already have access to Continental, Delta, and American Airlines lounges when flying same-day on those airlines’ flights. Now those higher-end Amex cards (with hefty fees) will offer US Airways lounge access as well, and interestingly with no same-day flight requirement as with the other lounges. So if you’re flying on another airline out of a terminal with a US Airways lounge, the card will actually get you in.

I’ve long recommended the American Express Platinum as a great road warrior card, combining the Membership Rewards points program (that comes with less expensive Amex products) with lounge access the airlines usually charge for along with benefits like the Fine Hotels and Resorts program. The card used to be even better with free domestic companion tickets four times a year, oh for the good old days.

Lucky thinks that once United and US AirwaysContinental merge, the Amex Platinum will get you access to all of hte legacy airlines’ lounges (they’re currently only missing United Red Carpet clubs). My bet is the opposite.

It’s interesting that US Airways is offering lounge access with the card even when not flying on the airline, they’re looking at this as a straight revenue play from American Express. Other airlines may want to entice Amex cardholders to actually fly the carriers but US Airways will just take the cash for lounge access. I wonder if this presages a return to the US Airways partnership in the American Express Membership Rewards program, the airline is pretty big on straight selling miles and Amex is a potentially big customer. Of course the airline pulled out of the program when it was acquired by America West with funding from new credit card partner Juniper Bank (now Barclays). I ssupect their contract will still preclude a bigger Amex relationship at least in the near-term.

But it’s those credit card relationships which make me wonder whether American Express will be able to retain Continental Presidents Club acess rights for their cardholders once Continental and United merge (and whether Continental will remain as a points transfer partner in the new entity).

It’s worth remembering that Chase, which issues both the United Visa and Continental Mastercad, has been playing in the premium card market more recently with offerings like the Continental Presidential Plus Mastercard which offers lounge access and status with Hyatt and Avis as well as bonus miles for elite members flying the airline. And they’ve offered packaged lounge access cards with United as well.

And Chase has enormous sway at United. The issuer of their co-branded credit card provided the debtor-in-possession financing for the airline’s bankruptcy, as well as the exit financing, and massive liquidity through the pre-purchase of miles. My bet is it’s unlikely they’ll allow another credit card issuer to offer United lounge access, or to act as a transfer partner essentially allowing you to earn United miles through American Express spend.

So while there may be a brief time that cardholders have lounge access with Continental after the merger, once the current contract with Continental ends I have a hard time imagining that it’ll be renewed.

And speculating even further, I’d guess that Amex expects that too — and it’s what got them moving to secure a newlounge parnter. That said, if my theory were true I’d also have expected them to wait to finalize the US Airways deal until the Continental deal was ending in order to announce the addition and loss together. That didn’t happen. Take that for what you will.