Combine water, sugar, vanilla bean (with seeds), citrus zest, cinnamon stick, and ¾ cup bourbon in a heavy saucepan. Bring to a gentle simmer, stirring until sugar dissolves, about 5 minutes.

Add the peeled pears upright and partially cover. Poach over low heat with soft bubbling around the edges, until a paring knife slides in easily, 20–25 minutes, turning once halfway.

Transfer pears to a plate with a slotted spoon. Continue simmering the poaching liquid until it thickens and coats the back of a spoon, roughly 15 minutes.

Discard the vanilla pod, cinnamon stick, and zest strips. Stir in the remaining bourbon and simmer for 2 more minutes.

Return the pears to the pan, spoon the syrup over them, and let cool at room temperature for at least 1 hour before serving or chilling.