Yes, I was wondering this as well - does it mean supplementary cardholders, as well as other cards linked to the same Ascent program, aren't eligible for the bonus points? It did specify that only the card indicated on the front of the letter (in my case, the Platinum Credit Card) was eligible.As per the previous post, the other thing I note is the restriction on card number e.g. my supplementary that my mother has, doesn't seem to be covered under this promo.
I have only recently obtained a Platinum Charge Card and have all my other Amex charge and credit cards (including my Platinum Credit Card) linked to the MR Ascent Premium program, so I'm not sure which cards are covered.
I guess this will have to be tested once the promotion commences, which is conveniently straight after the Earth Platinum promotion ends...