Combine the wine, sugar, orange zest, orange juice, spices and vanilla in a medium saucepan or a small Dutch oven and simmer over a medium heat. Heat until the sugar dissolves and the mixture starts to simmer, about 5 minutes. Gently lay the pears down in the saucepan. Reduce the heat, cover the pot and simmer slowly for about 25-30 minutes. Rotate the pears often so the wine sauce coats them evenly.