Yes, some people not staying at a resort have received the credit dining at a resort restaurant. See, e.g., Post 65, supra.

https://www.flyertalk.com/forum/amer...l#post36026466 (Post # 65)

It all depends on how the charge is coded. If the restaurant has its own separate merchant code, no credit will be received. If the resort's merchant code is used, it will bill as a charge from the resort, resulting in a credit.

The safest way to find out might be to visit in advance, and make a very small test purchase.