In a large resealable plastic bag, combine chicken breasts and 1/4 cup dressing. Seal, and refrigerate for several hours.
Preheat grill for high heat. Combine sun-dried tomatoes and hot water in a small bowl. Set aside for 10 minutes, drain, and cut tomatoes into thin slices.
Lightly oil grill grate. Discard marinade, and place chicken on grill. Cook for 12 to 15 minutes, turning once, or until done.
Cut chicken into strips, and place in a medium bowl with sliced tomatoes, feta, and spinach. Toss with remaining 1/4 cup dressing. Distribute mixture between the four tortillas, and wrap. Either cut in half and enjoy cold, or place briefly back on grill until the tortilla turns warm and crispy.
