The pilot stated that the airplane bounced and became airborne after landing firmly on the runway. As the airplane settled back onto the runway it veered to the left despite his control inputs. The airplane subsequently veered off the runway and ground looped. Examination of the airplane revealed that the left and right wings were structurally damaged. The tail wheel rudder spring attachment bolts were found separated and were located on the runway. The fracture surfaces of the bolts were consistent with overload. The pilot reported no pre accident anomalies with the flight control system.