I woulldnt bother, unless the standard one is leeking, or you like the aftermarket sound.
In an Auto the BOV is less critical than in a manual as when accelerating you dont take your foot off of the accelerator, hence you dont get the sudden shock wave that occurs when the boost hits a closed throtle.
If in doubt, just remember that Veilside in JP dont bother with BOV on their factory cars at all, as they consider the benifits not worthy of the weight and potential for problems. (but they are prepared to rebuild their turbos more often than I would like)