Yes, that product will benefit from a starter. It is a blend of Saccharomyces and Brett. According to an article in the most recent BYO
http://byo.com/stories/issue/itemlist/category/200-may-jun-2014
, Brett propagates slower than Saccharomyces, so more time would be required on the stir plate to achieve maximum Brett growth.
I actually just pitched WLP670 for the first time last Tuesday. I did not have time to prepare the starter further in advance, so I used my starter SOP–which is to prepare the starter the night before brewing and pitch in 16-24 hours. As I understand it, Brett works slowly anyway–so there may not be a meaningful difference in time or outcome. I would (and do) plan on letting that beer age for a while.