Staff has never given me a problem taking a family member or two (typically on award tickets, separate PNR from my paid one) with me to elite check-in, elite boarding, or whatever.

My wife had a serious guilt complex about it the first time, though. "Are you sure we're supposed to be in this line? It says business class! Wait, why are you cutting in front of all these other people? Shouldn't we get in line at the back?"

My daughter, on the other hand, rather liked the idea of getting special treatment, lounge access, and all that stuff. She still complains that domestic F seats are too big for an 8-year-old, and there's too much food, but other than that, I guess she just takes it all in stride as small steps on her path to eventual world domination.