TOSS water chestnuts with teriyaki sauce. Let stand 10 min.; drain.
HEAT oven to 375ºF. Brush crackers with syrup. Top each with 1 water chestnut slice; wrap with bacon piece, overlapping ends under cracker. Place on foil-covered baking sheet.
BAKE 25 min. Heat broiler. Transfer topped crackers to broiler. Broil, 6 inches from heat, 3 min. or until bacon is crisp. Transfer to plate; top with mustard and peppers.