In a medium saucepan, warm ¼ cup of the olive oil over medium-low heat. Add the onion, half the garlic, ½ teaspoon of the chile powder and ½ teaspoon of the paprika and cook until the onions soften, about 5 minutes. Add the grits and bay leaf and cook, stirring, for 30 seconds. Add the crushed tomatoes, corn, ¼ cup of the white wine and 3 cups of water. Reduce the heat to low and simmer the grits, stirring frequently, until the liquid is absorbed and the grits are creamy, about 25 minutes. Discard the bay leaf and season to taste with salt and pepper.
Meanwhile, in a small bowl, combine 2 tablespoons of the lemon juice with 1 tablespoon of the remaining olive oil, the remaining ½ teaspoon of chile powder, the remaining ½ teaspoon of paprika and the shrimp. Let sit for 15 minutes at room temperature.
In a medium skillet, cook the shrimp and remaining garlic over high heat, stirring, until just pink, about 2 minutes. Add the remaining 3 tablespoons of olive oil, the remaining ¼ cup of white wine, the remaining 2 tablespoons of lemon juice, the cherry tomatoes and the cilantro and parsley and cook for 2 minutes longer. Remove from the heat and season to taste with salt and pepper.
Divide the grits among 4 shallow bowls. Top with the shrimp, tomatoes and sauce and serve immediately.