Question for you wise folks:

My wife had (emphasis on past tense) a B of A AmEx. It was opened just before the current enhanced 38K mile offer, so her signup bonus was only 10K miles.

Long story short, we closed the card because B of A consistently refused to upgrade her signup bonus to the 38K offer, which I got. About a week after her card was closed, we got some mail from B of A, including the 10K mile cert plus the lounge access coupons, in my wife's name. I also received mine a short time later. (As an aside, we were surprised that B of A just deposited her sign-up bonus miles in her Asiana account.)

Anyway, we have a big family trip planned. We plan to split the team: wife and kids on Asiana, and myself on a different carrier. Asiana says that my 10K cert is valid for use only if I am traveling. And I'm not flying on Asiana. So I was wondering, what kind of exposure would we have using the wife's 10K cert which was connected with her now-closed Asiana AmEx?

We're about 8K miles short of what we need to cover all the Asiana tickets with miles, so we want to use one of the 10K certs. I should mention, my wife is an AU on *my* Asiana AmEx.

An alternative is to pay the fare for my youngest, who is a Magic Miles member (75% fare). Thanks in advance for helpful comments, insights, etc.