Combine first 4 ingredients in a bowl; stir well. Set aside.
Cut bell peppers in half lengthwise; discard seeds and membranes. Flatten bell peppers with hand. Coat bell pepper halves, onion, eggplant, and zucchini with cooking spray. Place bell pepper halves, skin sides down; onion; eggplant; and zucchini slices on a grill rack. Cover and grill 5 minutes. Turn onion, eggplant, and zucchini slices over (do not turn bell pepper halves); cover and grill 5 minutes or until onion, eggplant, and zucchini are tender. Remove onion, eggplant, and zucchini from grill. Grill bell pepper an additional 5 minutes or until blackened. Place bell pepper halves in a zip-top plastic bag; seal. Let stand 10 minutes. Peel bell peppers, and coarsely chop all vegetables.
Combine chopped vegetables, Caesar dressing, and salt in a large bowl; toss gently.
Spread about 3 tablespoons cream cheese mixture over each flatbread. Spoon 1 cup vegetable mixture onto 1 short end of each flatbread; roll up wraps. Cut each wrap in half crosswise, and secure with a wooden pick.