In a large skillet, heat oil over medium-high. Season fish with salt and pepper, and sear, skin side down, for 4 minutes. With a wide metal spatula, turn fish over and cook 1 minute. Do not cook through. Remove from the pan; set aside.
Add onion to the pan, reduce heat to medium, and cook, stirring occasionally, until onion is tender and the edges begin to brown, about 4 minutes. Add garlic and cook 1 minute.
Add jalapeno, wine, 1/4 cup water, corn, tomatoes, and fish, skin side up. Cover and cook 4 minutes, or until the fish is just cooked through; transfer, skin side up, to four wide shallow bowls. Stir basil and cilantro into vegetable mixture and spoon around fish.