Once your surgical wounds are fully closed (that doesn't mean fully healed and matured which takes about a year), you can apply any lotions or sprays.
Because each surgeon has different personal preferences, you should check with your Plastic Surgeon first. However, in general once a surgical wound is closed (which usually takes two days), you can get the wound wet or apply creams, sprays. A wound is closed when it's no longer seeping fluid... doesn't look wet and shiny.
Also, when most surgeons perform tummy tucks, they use drains. For as long as you have drains, you can consider the drain wounds as 'open' and should not get them wet, don't apply any lotions or sprays.