Of course it does. If you can reduce art to its barest components and concepts by using math... which we can... then it's mathematical in nature. The fact that it is not pure mathematics does not change this. And it doesn't matter if the artist or the viewer has any special feelings or emotions that allowed them to create/enjoy the art; especially not when we have every reason to think that those feelings only occur because we subconsciously recognize and are drawn to the underlying math. Indeed, in order for that to not be the case, you need to produce some other explanation for how we understand the world around us, an explanation that does not involve our brains utilizing subconscious math... which is effectively impossible without appealing to magic.
The problem is that the disagreement here is ultimately reducable to the question of whether we have free will. You need to have free will in order for your version of art to be true; but free will is either an illusionary artifact of the way our brain works, or essentially none of our modern scientific understanding in that regard is valid: if you make decisions because your brain is subconsciously running a complex series of algorithms/checklists in order to decide what to do, then free will is an illusion (and everything you do or think is math)... however, if this is not the case, then free will is entirely arbitrary; just a random stab in the dark... which we know can't be true because if it were our behavior wouldn't be as predictable as it is (and indeed, we'd be as likely to random walk off a cliff as we are not to); which leaves the free will advocates with the unfortunate necessity of inventing a type of free will that falls outside a logical and naturalistic reality.
If we have that kind of magical free will, then yes, you can claim there's something more to art than math.
If we do not have that magical kind of free will, then the creation of art, and our enjoyment therefore, is ultimately a mathematical process.
And important: Not all art is meant to be aesthetically pleasing.
Yes, and generally the only people who consider that kind of 'art' to be art are the artists themselves and the art critics who want to feel relevant.