Yeah, an area is ok. Most commonly there is only one roof with pumps so it's a little simpler to put the amenity=fuel on that. In this case with multiple pumps an area is a good choice. Thanks for the response.

Hi RunningDroid, there should only be one amenity=fuel object per location, you can use man_made=fuel_pump for multiple pumps/areas. See amenity=fuel?uselang=en