Originally Posted by Wasabi Tofu

If your accounts are combind correctly, no problem. To confirm, call AMC desk.

I have several ANA credit cards.
For example, Tokyo metro ANA card has a different AMC number (3zz-xxx-xxxx).
Metro points are converted to ANA points to that AMC number (3zz-xxx-xxxx).
However, it is correctly credited to my main AMC number (3qq-yyy-yyyy).

You can use any AMC number to log in to ANA web.
However, SKIP service and flight reservations are bound to the specific AMC number(a.k.a. main card).

You may visit FAQ section, and search by 'main card' and 'number change')