Place the pears, wine, and water in a small saucepan and bring to a boil over high heat. Turn heat to medium-low and simmer until pears are soft, about 5-10 minutes. Remove pears from wine and reserve.
Place the sweet potatoes into a large pot and cover with water. Bring to a boil over high heat, then reduce heat to medium-low, cover, and simmer until tender, about 20 minutes. Drain and allow to potatoes to steam dry for a minute or two.
Stir the reserved pears, evaporated milk, vanilla, brown sugar, butter, cinnamon, and nutmeg into the sweet potatoes and mash until smooth. Transfer to a serving dish and serve hot.