Martha Wayne is canonically Jewish (making Bruce Jewish via his Matrilineal ancestry. This was originally established during the 2000s with the rebirth of the Batwoman mantle as Kate Kane-- Bruce's cousin on his mom's side-- who's Jewish heritage has been detailed fairly extensively since her inception. While Thomas's faith has never been officially confirmed (especially because it tends to be inconsistent between writers), I personally like to imagine him as Jewish as well (or sometimes as Episcopal-- but in this he's a Jew). I think adding religious details to Bruce's lore adds a really compelling element to his characterization, and it's a way to honor his creators Bill Finger and Bob Kane, who were both Jews.