Arrange fish in one layer in a 13 by 9 inch baking dish. Sprinkle with 1/4 teaspoon salt. Using a food processor or blender, puree 1/2 teaspoon salt, cilantro, onion, sugar, chile, lime juice, tequila, oil, and garlic until smooth. Spoon mixture overtop of fillets and flip to coat. Let rest in refrigerator for 30 minutes, flipping once.
Take fish out of dish and lay on cooking spray grill rack. Cook 5 minutes per side or until fish is flaky. Top with cilantro and lime wedges.