Heat 1 tablespoon of the oil in a skillet and cook the bacon until golden-brown. Remove the bacon from the pan with a slotted spoon and reserve. In a separate skillet heat 1 tablespoon of the butter and the remaining oil and cook the onions until golden-brown. Brown the rabbit pieces in the skillet where the bacon was cooked, over a moderate heat. Season the rabbit pieces with salt and pepper. Stir the wine, garlic, and bouquet garni into the skillet. Bring to a boil, reduce heat to a simmer and cook for 35 minutes. Add the pearl onions and chestnuts and cook for 10 minutes longer.