Combine wine, garlic, and 1 teaspoon rosemary in an 8-inch square baking dish.
Sprinkle fish with salt and pepper; place fish in baking dish, turning to coat. Cover and chill at least 1 hour. Remove fish from marinade, discarding marinade.
Coat food rack with cooking spray; place rack on grill over hot coals (400° to 500°). Cook fish, covered with grill lid, over hot coals 4 to 5 minutes on each side.
Combine remaining 1 teaspoon rosemary, lemon juice, and olive oil. Spoon over fish, and serve immediately with lemon wedges, if desired. Garnish with sprigs of fresh rosemary.