Originally Posted by
MSPeconomist
OTOH AmEx has a lounge agreement with DL that all Plat and Centurion cardmembers can access the DL SC (at ORD and throughout the system) when the passenger has a same day flight operated and marketed by DL. Certain DL AmEx cardholders get the same privilege. Given this, I would expect ORD to be a low priority location for a Centurion lounge.
Could be, as I'm sure the DL/Amex relationship is a delicate one. They have certainly cut down multi airline flexibility by limiting access to a same day DL flight. I'm never on DL going into ORD; usually puddle jumping in on UX before catching a TCON flight.