The prayer "Me'en Sheva" or "Magen Avot" which is recited in shul in Friday nights after the silent Shemoneh Esreh was instituted to accommodate late-comers so that people would walk home from shul together to avoid dangers.
Shulchan Arukh, Orach Chayyim 268:10 says:
אין אומרים ברכה מעין שבע בבית חתנים ואבלים דליכא טעמא דמאחרין לבוא שיהיו ניזוקין:
In brief, in a house that has a groom or mourner, this prayer is not said, because there is no concern of late-comers.
Some commentators have explained this concept that a non permanent "place" that does not have a regular minyan doesn't require saying this prayer.
In a few months, my friend's son will have his aufruf in a hotel. This hotel occasionally has Jewish groups and they set up a room for a minyan, when needed. However, it is a hotel - not a shul. But it is also not someone's home - it's a public place. It's not exactly as the Shulchan Aruch describes.
Does the Shulchan Aruch's principle apply to davening in a hotel Friday night?