PREHEAT grill to medium-high heat. Cut steak into thin strips. Place 1/4 of the steak strips in center of each sheet of foil; sprinkle with garlic powder and black pepper. Top with pepper strips; drizzle with teriyaki sauce.
BRING up foil sides. Double fold top and ends to seal packet, leaving room for heat circulation inside. Repeat to make 4 packets.
PLACE packets on rack of grill; cover grill with lid. Grill 7 to 9 minutes or until steak is cooked through and vegetables are tender. Serve over rice.