Combine wine, onion and shallots in medium saucepan. Boil over medium-high heat 5 to 7 minutes or until reduced to 1/2 cup. Add cream and cloves; reduce by 1/2.
Reduce heat to medium. Slowly whisk in butter, piece by piece, until butter is nearly all melted and incorporated. Remove from heat; continue to whip until smooth. Add capers, salt and pepper. Discard cloves.