I certainly could be wrong here, but I was going by Amex's web site where you enroll cards. There are card categories there including the Delta Amex Gold card. Platinum is not specifically mentioned, but as it is new, I figured it just wasn't added to the options yet.

However, I don't have one of the affinity cards, so have never tried to enroll one personally. I should have mentioned this in my last post rather than making a blanket statement.

Has anyone tried this, and what were the results?