Pour 2 tablespoons of olive oil, red wine vinegar, garlic and herbs into a one gallon size re-sealable bag. Season chicken with salt and pepper. Add the chicken to the bag, seal and massage mixture all over chicken. Set aside, turning occasionally while preparing veggies.
Place sweet potatoes, Brussels sprouts, apples and red onion on a large rimmed baking sheet. Drizzle with remaining 2 tablespoons olive oil, gently toss to coat. Season with salt and pepper to taste. Spread into an even layer, then place chicken over the veggie/fruit mixture. Discard marinade. Scatter bacon pieces evenly over veggie/fruit mixture.
Roast in preheated oven until chicken and veggies are golden brown, about 30 minutes (chicken should register 165 degrees in the center). Broil during last few minutes for a more golden skin on chicken if desired. Serve immediately.