Combine chicken and 1/2 cup dressing in a large zip-top plastic bag. Seal bag; marinate in refrigerator at least 2 hours, turning bag occasionally.
. While chicken marinates, combine artichoke and remaining 1/4 cup dressing in a small bowl; cover and refrigerate.
. Prepare grill.
. Cut bell pepper in half lengthwise. Discard seeds and membranes. Flatten pepper halves with palm of hand.
. Remove chicken from bag; discard marinade. Place chicken and pepper halves on grill rack coated with cooking spray. Cook chicken 5 to 6 minutes on each side or until done. Cook pepper halves, skin sides down, 10 to 11 minutes or until charred. Discard charred skins. Slice chicken and bell pepper into strips.
. Add lettuce, tomato, and onion to artichoke mixture; toss gently.
. Spread 2 tablespoons hummus over each tortilla; arrange chicken and bell pepper evenly over hummus. Top evenly with artichoke mixture; sprinkle evenly with feta cheese. Fold top and bottom of each tortilla toward center; roll up burrito-style (wrap will be full). Secure with wooden picks, if necessary. Serve immediately.