Reading the NEC definitions, IF this pool house is detached from the dwelling unit, I would have to say no receptacle is required.
The 'pool house' does not qualify as a dwelling unit, in and of itself. The same would apply to a detached garage (man cave) with a bathroom, unless it had all the items within the dwelling unit definition.
Now, from a design side, why not install the receptacle with GFI? Although Reno leans toward the GFI being a maintenance issue, it sure may prove to be a convenience item.
