2.3 weeks post op Hair Transplant, is it okay to get a spray tan?

Yes but it is always a good idea to follow up and check with your doctor.  I would want to be kept in the loop if you were my patient.

Following hair transplant, it is ok to apply products at the 2-3 week point.  Some would even say sooner than that would be ok.  If you are unsure, ask your doctor for advice.  I would imagine that he will be ok with you getting the spray tan, as the transplanted hair follicles are healed below the skin's surface at this point.

All in all,  you'll want to check with your hair transplant surgeon to confirm. But it should be fine. 

You can use spray tanning material after 3 weeks (one week after all of the crusts are off) without much risk. 

If you are healed then you can return to your normal routine.  If you like to get sray tan then it is alright . I recommend to get advise of your doctor.