Here's a ebay listing that suggests that the release of the "Adventures" was during 1966, after the January debut of the TV series.

http://cgi.ebay.com/1966-Columbia-Pictures-Batman-Robin-Serial-Brochure_W0QQitemZ120383404917QQcmdZViewItemQQptZLH_DefaultDomain_0?hash=item120383404917&_trksid=p3286.c0.m14&_trkparms=66%3A2%7C65%3A10%7C39%3A1%7C240%3A1318#ebayphotohosting