Originally Posted by
WineCountryUA
While separate reservations can not be combined (especially if a different itinerary), one (an UA elite) can request a (single) companion on the same flight to be guested into E+ to join you. Does not require to be a single PNR but does require a call and requires you also are in E+ (and not in a premium cabin). Can be done any time.
I know this was true before, but is it still true now? This
link indicates that companions need to be on the same PNR.