That's an interesting question that I think depends on the age of the kids and where they are developmentally. At the younger ages, all the kids have problems throwing strikes to a batter who has already squared around. Lots of coaches have their kids fake bunts to distract the pitcher and try to draw walks. The best way to get the pitchers accustomed to throwing to a bunter is to have them practice throwing to bunters in practice. I thought of it as a part of practice like pepper with a purpose. Hit the bat.
Once they get over the mental hurdle of being comfortable with a bunter, the next level development is to try to attack the bunter. I thought the kids to throw the ball at the bottom of the letters down the middle, trying to produce pop ups. Throw the ball higher than the bat at the top of the strike zone, teach them we want the bunter to raise the bat to make contact. Once they get comfortable with the idea of changing their target once the bunter squares, there are other quick decisions they can learn to make that are situation dependent.
Like everything else, it's a layering process of getting the kids comfortable with one level before moving to the next.