If a location required everything to be 'hospital grade,' then both cap and recep would need to meet the requirements. However, there is nothing that forbids placing the appliance in other locations.
"Hospital grade" simply means that the devices meet tougher criteria. Indeed, the practice of sever manufacturers is to simply pull product off their regular production line, and stamp those specific pieces that meet the higher standards. In terms of ordinary use, the components are perfectly interchangeable.
Hospital grade means they have to conform to certain hospital UL standards and are built better than the average cheap plug, but they still conform to NEMA 5-15 and all applicable standard UL listings for plugs. It's perfectly acceptable to plug a hospital plug into a non-hospital receptacle.
Steve- Based on your reference to "interpower" (which was excellent) I feel that it would be reasonable to look for a hospital grade receptacle when inspecting the job since the grounding is the whole reason for installing the hospital grade cap on the cord. The hospital grade receptacle would provide similar standards and be compatible with the cap. Am I in left field?