Has anyone had experience with using the same credit card in their actual amazon.com account (which email also has an amazonpayment.com) and a different amazonpayments.com account?

In my case an am ex account is linked to amazonpayments account B which is used sometimes to send $ to amazonpayments account A. Account A has the same email as my actual amazon account.

I have an amex account for AP account B linked to my twitter amex offers which hasn't been an issue in the past but now there is a twitter deal where if I charge $75 on that account on amazon I'll get a $25 credit.

I don't want to add that amex to my regular amazon account and end up getting my AP account closed over $25.

I know AP is a different entity from Amazon but not sure if it's worth the risk