Place large sheet of foil over half of grill grate. Pour 2 T of the dressing over chicken in resealable plastic bag and seal. Turn bag over several times to evenly coat chicken with dressing. Refrigerate 10 minutes to marinate. Remove chicken from marinade and discard marinade bag.
Grill chicken on uncovered side for 6 minutes. Meanwhile, combine tomatoes, cheese, basil and remaining 2 T of dressing.
Turn chicken over and place cooked side up on foil on grill. Top evenly with the tomato mixture. Close lid. Grill an additional 8 minutes until chicken is done.