Preheat the oven to 425°F.
In a large bowl, combine the shallot, garlic, lemon zest, anchovies and rice wine vinegar. Let sit for 30 minutes, then fold in the olive oil, tomatoes, capers and salt to taste.
In a small saucepan, combine the couscous, olive oil, 2 cups of water and ½ teaspoon salt. Bring to a simmer, turn off the heat, cover and let sit for 15 minutes, until the grains are tender. Fluff the couscous with a fork and fold in the raisins, olives, bell pepper, capers and parsley.
Place the branzini on a baking sheet, drizzle with olive oil and sprinkle liberally with salt and pepper, including the cavity.
Heat a large ovenproof or other skillet over high heat. Add the branzini and cook for 3 minutes per side, until the skin is crisp. Transfer to the oven (using a baking sheet if you don't have an ovenproof skillet) and roast for 8-10 minutes, until cooked through.
Divide the warm couscous salad between plates, top with branzino and drizzle with tomato anchovy vinaigrette.