Why wouldnt they?
Just providing a data point, mostly in regard to the timing of posting. The T+C indicate it shouldn't work:
"Good to Know
This benefit doesn't offer credit toward airline tickets, mileage points purchases or mileage points transfer fees, gift cards, upgrades, duty–free purchases, or award tickets."
2 separate accounts? What's the chidush?
$209 was credited?
Just pointing out that the purchase could be for any traveler; doesn't need to be for the cardmember. Not a big deal. Only $200 was credited, as expected.