Mix chilli powder, garlic powder, onion powder, sugar, salt, allspice, cumin, white pepper, and paprika In a small bowl.
Keep 1 1/2 tablespoons of the mixture for the vinaigrette, and sprinkle the rest over salmon fillets. Cover, and refrigerate for 6 hours.
Preheat the grill to high heat. Lightly oil grill grate, and spread a small amount of olive oil on salmon fillets.
Grill salmon for 4 to 5 mins per side (skin side up first), or until easily flaked with a fork.
Mix together tomato-vegetable juice cocktail, vinegar, tomatoes, olive oil, and reserved spice mixture to make vinaigrette in a small bowl.
Place salad greens in a bowl, sprinkle with vinaigrette and toss to coat.
Divide greens among individual serving plates. Top each dish with a salmon fillet, and spoon any remaining vinaigrette over the salmon.