There is a bus from Bray to Sandyford Luas run by the local company, Finnegans. I don't think integrated fares are available, but check with them if 10-journey or weekly tickets are available.
http://www.finnegan-bray.ie/page11.php
Alternatively, Dublin Bus route 145 will drop you on the N11, a bit away from Sandyford.
The 114 from Blackrock DART station also goes to Sandyford and integrated DART-bus tickets should be available.
Dublin Bus's Network Direct propject will revise a lot of routes, partially to improve connections to Luas and the extension to Cherrywood.