It is common for instructors to pay more attention to the male partner, for some good reasons, like leaders' slower learning curve and the fact that there are lots of things the leader can do that will make it either easy or impossible for the follower to do what she's supposed to do.
There could be other factors at work here:
--if your partner was badly trained (in your instructor's opinion), there may be 16 years worth of bad habits to correct.
--since you are relatively new, he may be focusing on your partner to get him as perfect as possible for your sake--so you can learn your part easily without your partner messing you up and so you won't have to develop bad habits to compensate for your partner's mistakes.
On the other hand, there are some less than great reasons this may be happening:
--there are some teachers who believe that 80% of dancing is the leader's responsibility, that the woman "just follows." Personally, I wouldn't want to take lessons from someone who felt that. It's much more rewarding as a follower to study with someone who believes the follower should be an active dancer.
--Is your instructor male? Most male instructors know the man's part much better and more thoroughly than they do the woman's part (and vice versa for female instructors). That's not to say they don't know the other part well, just that they know more nuances of the part they dance all the time. So he may see more problems with your partner because he knows that part more intimiately. Or he may be focusing on the male part because that's what he's most comfortable with.
In any case, communication is key to a successful partnership and a successful student/teacher relationship. Before you get upset, talk this over with your instructor and partner to see why this is happening. Then when you know, you can decide if you need to do anything about it.
One possibility (which I would recommend anyway) is for you and your partner to also take some coaching from a female instructor, so you can both get the benefit of the follower's perspective and the deeper knowlege of the follower's role.