I haven't had any reason to address my T by name. If I tell about him to my spouse then I say both first name and last name. It would feel weird to me to use only the first name. Now when I think about it, I guess I always refer this way to people when I talk about them, unless they are a close acquaintance, a relative or a friend.

My education level is higher than my T's but he does not address me by my title. But I started to see him when I had not earned my degree yet. Another T I saw meanwhile, who also had lower education level than me, always addressed me by my title, whereas I addressed him also by his first name and last name. But that happened only in emails - I don't see any reason to address someone by name if there are only two persons in the room, and I guess neither did that T.