Tip the wine into a medium pan, then add the vanilla pod to the pan with the sugar. Bring to the boil, then reduce the heat and simmer until the sugar has dissolved.
Stone the cherries if you want, or leave them as they are. Add to the pan and cook gently for 6 mins. Remove with a slotted spoon to a bowl. Increase the heat, then boil the liquid for 8-10 mins until slightly syrupy. Pour over the cherries and serve warm or cold in glass bowls.