So there is no stacking, more like splitting. If this is the case, neither card is meeting their agreement with card holders.

I redeemed 110k today, and holds both Citi AA Plat and Barclay Aviator Red. The rebates already hit my AA account, and 4 rebates were listed, total 10k. If they stack in any meaningful fashion, I should have received 11k back.

I need to call AA sometime tomorrow. May ask the agents there, but I kind of doubt they would have the authoritative answer on this.