I'd say let Dr. Galland know that, and he will decide whether to retest or not. My guess is that he'll put you on an antifungal with an Antibiotic if you test positive for SIBO.
That surprises me that a single round of Antibiotics might cause Candida. It took me no less than a dozen rounds of Antibiotics before I got it. But there could be other factors at play in your case.
At any rate, Dr. Galland will sort it all out, of that I am sure.