katzinger is benadictine.
How do you know he's a Benedictine? Granted he took the name of "Benedict" which is pretty interesting, but I can't find any indication he is Benedictine.
Ratzinger is not a Benedictine. He is not any sort of order priest. He has gone to Benedictine monasteries for retreats, but it is not true that he is Benedictine. He is a diocesan priest.
From his biography on the Vatican website:
In March 1977, Paul VI elected him Archbishop of Munich and Freising and on 28 May 1977 he was consecrated, the first diocesan priest after 80 years to take over the pastoral ministry of this large Bavarian diocese.
Full biography can be read here:
http://www.vatican.va/holy_father/benedict_xvi/elezione/biografia_en.html