The visitors took the lead through Emile Sinclair but Wanderers came on strong in the second half with Tuncay scoring one and setting up Martin Petrov for the winner 17 minutes from time.
"Tuncay put himself in great positions and we know the ability he has," said Coyle, who has had to wait almost a fortnight for the Turkey international to become available because of work permit issues following his loan move from Wolfsburg.
"He hasn't trained with us for 10 days so for him to come in and show the desire and hunger from the start is a credit.
"He produced a terrific finish and he was desperate to get another.
"He will get better as he gets fitter."