I don't think Spock knows what year it is. Remember, Nero didn't know what year he'd arrived in.
Spock kneeling before Nero has led to some fabulous fan fic....(which is why huge gaping plot holes don't bother me that much). My best "in universe" explanation would be he's humbling himself before Nero because he knows he cannot fight him and thinks his only hope for survival is to not give him a reason to kill him.
Spock kneeling before beaming struck me as bizarre, but I figure maybe the only place they could send him was a hill (which is where he landed) so crouching with bended knees was less likely to result in him falling on his *** when he materialized.
Thanks to Ron Salon for the signature banner!