Transfer American Express Membership Rewards Points to Air France-KLM Flying Blue, Get a 25% Bonus

American Express is currently offering a 25% transfer bonus to Air France-KLM Flying Blue, letting you book some fantastic award flights for a little less. Here's what you need to know about this rare Amex-Flying Blue transfer bonus and some of the best ways to maximize it before it takes flight on June 30, 2026.