Remember, AMEX provided $600MM in pre-bankruptcy fnancing, the initial Debtor-in-Posession financing with the 2005 Chapter 11 filing and, while I'm not sure of the specific date, bought $1B Skymiles (at a very deep discount) which they couldn't use for at least 5 years. These skymiles are now unrestricted and being used by AMEX and probably are a mix of RDM's and MQM's.

The only thing that's surprised me is that when the change to AMEX Platinum (non-DL Branded) no longer having guesting privileges at Sky Clubs took place, that AMEX reps claimed they didn't know anything about it. I'm certain it was worked out between AMEX and DL so that that it wouldn't look like a reduction in benefits by AMEX while giving them a nice reduction of expenses and DL an opportunity to increase revenue and profits,

Back to the OP's original question. When you look at everything in the AMEX / DL relationship, it's probably close to a break-even. I doubt that there's anything done by either organization that affects the relationship or the $, and particularly cash flow, that isn't worked out beforehand.