What I appreciated most about the hook up was that it was tied into the backstory of Sarek falling in love with Amanda. The writers tied it into established family history, they tied it into Spock's conflicts with his "half-breed" nature, and then they also tied it into the future of the Vulcan race.
There are lot less Vulcans for Spock to "date" now. Spock says Earth is now the only home he has left, and he loves a human woman. There's a lot behind those simple lip-smacks!
I know what you mean about the circumstances of the beam-away scene, Eliza. I took it as that by this point in the story, Spock is becoming comfortable expressing his human side, his emotions, instead of repressing or fighting against them (and hiding their intimacy in turbolift trips). It wasn't like he kissed her on the floor of Starfleet HQ of course, but it would have been a public display of affection to him. It was another useful, dramatic way to show internal growth in his character.... very expressive in Vulcan terms.