In a large bowl, combine the first 11 ingredients. Coat four pieces of heavy duty (12" square) aluminum foil with nonstick cooking spray. Place a quarter of chicken mixture in center of each piece. Fold foil around mixture & seal tightly. Grill, covered over medium high heat for 15-18mins or until chicken juices run clear.
Carefully open each packet. Sprinkle w/ tomatoes & cheeses. Seal loosely; grill 2 mins longer or until cheese is melted.