Stir wine, garlic and 1 teaspoon rosemary together in a medium baking dish. Sprinkle fish with salt and pepper. Place in the baking dish, turning to coat. Cover and refrigerate for at least 1 hour.
In a small bowl, stir together the lemon juice, olive oil and remaining rosemary. Set aside.
Preheat barbecue to medium.
Transfer fish to a paper towel lined dish and discard marinade. Lightly oil barbecue hotplate to prevent sticking. Cook fish 10 minutes, turning once, until easily flaked with a fork. Remove fish to a serving plate. Spoon lemon sauce over the fish and top each fillet with a slice of lemon for garnish.