have been recently told by a flight instructor that the normal engine response time from idle to go around thrust which is normally 6-8 sec increases when the aircraft is at or below vapp to approx. 14 sec.
Simulator training for the Boeing 737 series of aircraft includes bounced landing recovery followed by GA. The airspeed could be as low as VREF minus 15 knots immediately following the bounce. From experience in the simulator, GA thrust is normally attained within 5-8 seconds from closed throttle idle. Airspeed has no effect