As I understand it a "commissionaire" is only used in British English (or so says the dictionary), but then what is the American English alternative?
Typically people use Doorman
a usually uniformed attendant at the door of a building (as a hotel or apartment building)
As in MacMillan Dictionary the alternatives are :
bellboy : a man whose job is to carry people’s bags to their room in a hotel
bellhop : a person whose job is to carry people’s bags to their room in a hotel
chambermaid : a woman whose job is to clean the bedrooms in a hotel
and from Wikipedia,
"A bellhop (North America) or hotel porter (international) is a hotel porter, who helps patrons with their luggage while checking in or out. Bellhops often wear a uniform (see bell-boy hat), like certain other page boys or doormen. This occupation is also called bellman and bellboy."