Thaw fish, if frozen. Preheat oven to 350 degrees F. In a large skillet cook tomatoes in olive oil over medium heat about 6 minutes or until softened and skins begin to split. Add garlic; cook and stir about 1 minute or until fragrant. Remove from heat and stir in olives, raisins, capers, and oregano. Transfer to a shallow 2-quart baking dish.
Season tilapia with salt and pepper and place on top of vegetables. Bake, uncovered, for 20 to 25 minutes or until the fish begins to flake when tested with a fork. Sprinkle with chili powder and snipped cilantro, if desired. Serve with lime wedges.