I just came back from a Transcon JFK-LAX in C and back - was sitting next to my girlfriend (who has no status). As soon as the plane started to taxi the FA came to me and asked, "Good morning Mr. Lee, what would you like to have for breakfast" After I gave her my order she said thanks and bounced away - without taking my g/f's order. It was pretty comical - she came back later and curtly asked her, "we have eggs or a fruit plate, what would you like?"
I think this seat mate thing is completely random - but most of my seat mates have been asked right after my order was taken though...