Well, I had a couple of reactions to your hypothetical. I'll give you all of them for the sake of a complete answer.

The knee jerk reaction was this: the horse doesn't "like" your trainer? Are you sure you aren't suffering from a mild case of the Black Stallion Complex (i.e. "he's a beautiful wild stallion and only I can ride him")? Does your horse really not like the way your trainer rides or does your horse just not like being put to work? Because it is entirely possible that the reason he seems to like your riding better is because you are an amateur and probably don't push him as hard as your pro.

However, upon further thought, the previous really doesn't matter does it? Regardless of the validity (and I'm not doubting you at all, just throwing it out there in a hypothetical) of your claim, you, the client, are unhappy. As an unhappy client, you should sit down with your trainer and have a discussion. If he is a good professional, he will be able to set you in the right direction - be that by changing his methods with your horse, with you, or by pointing you in the direction of another professional who might be more suited to your needs.