In looking at your picture I see what looks like a mark on the wheel that could be damage that started this peeling.
The actual adhesion of that coating is the another issue.
You are spending a lot of money on this project but thats your business.
I would just keep in mind that what you are talking about now by Powder coating would leave you nearly as vulnerable to damage as what you have.
Adhesion to Aluminum is a touch and go issue.
Sandblasting the wheels will probably leave them with a Satin finish. If you color coat them it will be covered up, but if you want to clear coat again you might not get the gloss level you are expecting.
I would take the time to have a clear and concise discussion with the owner of the Powder Coating firm before you jump in.
Warranty at this point should be part of your discussion.

Good luck with your choice.

SF