Pour 1/4 cup Wish-Bone® Italian Dressing over chicken in large, shallow nonaluminum baking dish or plastic bag; turn to coat. Cover, or close bag, and marinate in refrigerator, turning occasionally, 30 minutes to 3 hours.
Remove chicken from marinade, discarding marinade. Grill or broil chicken, turning once and brushing with 1/4 cup Dressing, until chicken is thoroughly cooked, about 12 minutes.
Toss romaine with remaining 1/4 cup Dressing in large serving bowl. Top with tomatoes, cheese and croutons. Serve with chicken.