Data Point

Grand Rapids Michigan: The Amway Grand Plaza, Curio Collection

Starbucks location in Amway Grand Plaza does not credit. Bought a gift card and no credit

They have about 8 eating places plus a gift shop. Restaurants include Wolfgang Pucks, Ruth Chris Steak house, etc..

Amway does not sell Hilton gift Cards. However they do sell Amway gift cards that can be used only at that location for any restaurants/pubs (including Starbucks)
Bought an Amway Plaza gift card and got the 50 dollar credit. for my amex Bus. Platinum

Not sure if going to restaurants or the gift shop at the Amway Grand Plaza will trigger the $50 credit . Best to go to the hotel front desk and ask to buy a $50 Amway gift card for a sure credit

When the Amway charge posted, the classification was fast food restaurants lol. However, it posted as The Amway Grand Plaza, the Curio Collection by Hilton on the top line

Mostly if you see hotel or Hilton in your charge, the credit typically posts

One last thing. Trying to buy a Starbucks gift card with an Amway Grand plaza gift card does not work. So dont try it lol