Originally Posted by
thedlr
May 15 - purchased a one way flight for $108.99 May 20 - meter moved May 21 - reimbursement appeared dated for May 20
The previous high fare reported as reimbursed was $108.98 (several) so you now hold the record.

It's possible that even a slightly higher amount is reimbursable but no one has yet found the answer.
Reminder: There is no provision or entitlement for AmEx credit on airline tickets. It is a nice unwritten benefit that occurs with just a couple of airlines.