I tried this, and no dice from SMS or DL ticket counter. They can't split me out of the itinerary because the second passenger is traveling "attached" on a special/promotional L, U or T fare. She's medallion, too, and they won't even do it. They say the computer blocks them from adding me or her to the complimentaty upgrade request list.

Has this worked for you in the past, and (if so) what did you say/do to make it happen? Thanks!

I can't find a link to substantiate, but I booked at the American Express Travel Office in Orlando using an Amex comanion ticket a few days ago. You could find your nearest office and call to verify.