Wheel of the wizard! seems an invented exclamation from a tale. But, how can we connect a wheel with a wizard?
Do you know the meaning of "wheel" here, with a wizard being around?
I assume that came from here: "Night School" - a Story of Sembia by Clayton Emery ?
The author uses a number of colorful expressions:
Nine gates to the night!
Wheels of fire!
Wheel of the wizard!
Guts of the gods!
Wheels of the wizards
As far as I know, none of these have any particular meaning. They were simply invented to sound like something a "sword and sorcery" adventurer might say.
As suggested, it is far more likely that the writer [I cannot call him / her an author] is trying to create a phrase that sounds like something magic. These "novels " are dangerous to a learner of English since most contain words and phrases that only remotely connect to English.