Place fish in a heavy-duty, zip-top plastic bag. Com- bine lime juice, tequila, and olive oil. Pour juice mixture over fish; seal bag, and shake until fish is well coated. Marinate in refrigerator 30 minutes. Remove fish from marinade, reserving marinade. Place marinade in a small saucepan; bring to a boil. Remove from heat, and set aside.
Cut peppers in half lengthwise; remove and discard stems, seeds, and membranes.
Coat grill rack with cooking spray; place on grill over medium-hot coals (350° to 400°). Place peppers and onion slices on rack; grill, covered, 7 to 8 minutes on each side or until tender, basting occasionally with reserved marinade. Cut peppers into thin strips, and cut onion slices in half. Set aside; keep warm.
Place fish on rack; grill, covered, 4 minutes on each side or until fish flakes easily when tested with a fork. Cut fish into large chunks.
Spoon fish and vegetables evenly down center of each tortilla; top with lettuce, salsa, and sour cream. Roll up tortillas, and serve immediately.