In a large saucepan combine wine, water, sugar and the vanilla bean. Bring just to a simmer. Add nectarines. Return to a simmer. Cook, uncovered, over medium-low heat for 7 minutes or until just tender, turning nectarines once or twice. Transfer to a serving bowl. Let cool 10 minutes. Return the cooking liquid to a simmer. Simmer until liquid has reduced by half, about 5 minutes.
To serve, remove and discard vanilla bean. Scoop ice cream and drizzle with honey. Top with poached nectarines and the reduced syrup. Add mint leaves, if desired.