Sous Vide leg of lamb WITH bone?
According to Kenji Alt's experiements (admittedly with beef), the major effect of the bone is insulation, which matters in a high-heat cooking environment, but not in sous-vide.  See: Do Bones Add Favor To Meat

For sous-vide cooking, the bone adds little value, other than appearance.

It may also make it harder to put the product in your bag and seal it without a puncture.

Still, there should be no harm in leaving it on if you choose to.  In his ultimate steak method, Kenji Alt does leave the bone on for the sous-vide process.