Combine first 6 ingredients in a large zip-top plastic bag; add chicken. Seal and marinate in refrigerator 8 hours or overnight, turning occasionally.
Remove chicken from bag; discard marinade. Place chicken on grill rack coated with cooking spray; grill 4 minutes on each side or until done. Slice chicken diagonally into thin strips. Place bell pepper and onion slices on grill rack; grill 2 minutes on each side or until lightly browned.
Warm tortillas according to package directions. Working with 1 tortilla at a time, place one-fourth of the chicken strips, bell pepper, and onion in the center of each tortilla. Top each serving with 2 tablespoons salsa, 1 tablespoon cheese, and 1 tablespoon sour cream; roll up.