Ther are good connections from Amsterdam Schiphol airport to Ede-Wageningen. Duration of trip is is bit more than 1 hour (http://www.ns.nl/reisplanner-v2/index.shtml
). From there you can take a bus/taxi into the busstation of Wageningen (10-20 minutes or so) where the hotel is (http://www.hofvanwageningen.nl/?language=en), a 10 minutes walk from the bus station.
The bus from Ede-Wageningen trainstation stops at Alterra.