Soul is at the center of the circle of art.
Your word choices seem fine; I don't see a need to replace any particular word with a better-suited synonym.
However, I think there are better ways to express the notion of being at the center of a circle. I've made two fundamental changes to your original; these are:
I don't think we need to include the word point; the center of a circle is by definition a single point. I assume you are trying to express this in a poetic, philosophical way, and I think that can be accomplished more effectively by removing the word point.
Also, there is nothing grammatically wrong with art circle, although I think you'll find that, in English, expression the circle of X is used more frequently in this metaphorical context than the X circle (as is the sphere of X, as opposed to the X sphere). For example, expressions such as sphere of influence and circle of friends are quite common. Therefore, I think circle of art flows a little better than art circle.
My rewording is also a bit alliterative: the words soul, center, and circle are now all close together. That was just coincidental, but I think it works in the expression's favor.