In small bowl, combine marinade ingredients; remove 1/4 cup and combine with chicken in resealable plastic bag. Turn to coat; marinate in refrigerator 30 minutes or up to 2 hours, turning occasionally.
Meanwhile, in microwave-safe dish, combine potatoes and water. Cover and microwave on high 9-10 minutes or until just tender; cool. When potatoes are cool enough to handle, alternately thread with bell pepper and zucchini onto eight 10- to 12-inch skewers; brush with remaining marinade.
Remove chicken from plastic bag; discard marinade from chicken. Grill chicken over medium to medium-low coals 30-40 minutes or until juices run clear, turning occasionally. About 10 minutes before chicken is done, add vegetables to grill; reserve marinade.
Grill until tender and lightly browned, turning and basting occasionally with reserved vegetable marinade. Serve chicken and vegetables with tortillas and salsa, if desired.