Yes, WiaB is set ~20 years before SG. Both occur in Wollust, ZPR is formed from three families that appear in WiaB and characters from WiaB appear in SG (Emilio, Katie, Stefan appear so far, Zoey and Scarlet are mentioned and Miru is potentially mentioned and probably Ayua's mom). There are a lot of theories about people in WiaB being parents of various characters, as of yet, nothing has been set out conclusively, other than Ayua being a Zane, Sasha being a Petrova and the mysterious person on the first team who is a Revera.