In guild groups, I greed for companions, or simply ask in teamspeak if anyone minds that I roll need for a companion. In a pug, I feel that all loot is fair game. All 4 players participated and thus contributed to the success of the group so I feel everyone should have a chance to roll for loot that they will use (even if they use it on a companion).
^ This is how it should be, there is no reason a pug deserves an item more.
I'll be forming my own and making that clear though, and not re-invite those that need on everything. There is a gray area between never need for companions and always need on everything that drops after all.