Are political candidates coached to do this?

I have been involved in debate prep for a number of political candidates and yes, I have cached candidates to mention particularly people in the audience especially event sponsors and spouses. With that said, I think that the connections that you are referencing here are genuine because from my experience the coaching is more to thank event sponsors and immediate family for hosting the event and their support of the candidate's candidacy than it is to wave or make other off the cuff gestures.