MIX dressing and herbs; pour 1/4 cup over chicken in shallow glass dish. Turn chicken over to coat both sides. Refrigerate 30 min. to marinate.
HEAT grill to medium heat. Grill chicken 7 min.; turn over. Add tomatoes to grill; brush with 1/4 cup of the remaining dressing mixture. Grill 6 to 8 min. or until chicken is cooked through (165ºF) and tomatoes are heated through, turning tomatoes occasionally.
SERVE chicken with tomatoes and remaining dressing mixture.