From the long-distance train station at Frankfurt am Mainz Airport to the main train station in Mainz it is only 20 minutes by ICE and from the regional train station at Frankfurt Airport it is a 25-minute journey to the main train station in Mainz.
Time tables for the rain on can find here .
The conference centre Erbacher Hof is from the train station Mainz (Hauptbahnhof Mainz) within walking distance (1,4 km).
You can also go by bus from the train station to the Erbacher Hof. The closest bus station is Höfchen / Listmann, the bus lines are 54, 55, 56, 57, 58, 60, 62, 63, 68, 79, 80, 81, 90, 91, 93 from Hauptbahnhof West (there are two bus stops at the train station, bus stop Hauptbahnhof West, exit rail track 5 is more convenient).
The address of the conference centre is
Erbacher Hof
Grebenstr. 24-26
55116 Mainz
If you travel by car, corresponding maps are here .