Mix vinegars, honey, oil, and onions in a flat dish. Add chicken and mushrooms, cover, and place in refrigerator for an hour to marinate.
Preheat grill on high heat.
Remove mixture from fridge. Wrap the half slices of bacon around the chicken, and thread onto skewers, making sure bacon is secure. Alternate with pieces of pineapple and mushrooms.
Lightly oil grill grate. Place skewers on the grill. Grill skewers for about 20 minutes, brushing occasionally with additional marinade. They are done when bacon is crisp and juices run clear.