To me it sounds like "additional platinum cards" are diff versions of consumer platinum and "across all accounts" under the platinum. What could the all "accounts" refer to?
It just means that regardless of how many additional cards (read: authorized users) you have, the card account itself can only get $200 in credits, it doesn't matter who spends it.
Has anybody noticed a difference in speed of how Hotel Collection vs. FHR bookings are credited? I made a THC prepaid reservation with my MS Plat around Sept. 26 and the $200 was credited back within 3 days or so. I made an FHR booking on my Schwab Platinum card on Sept. 30 that hasn't been credited yet.