flew with ryanair last september which as u say lands at treviso.there is a ticket office in the airport for the bus which goes to venice --cost about �5.then u can either walk to your hotel or pref get the vaporetto .work out where the hotel is and get off at required stop (just like a bus but a boat)ryanair cancelled our flight home because of bad weather and more or less left us stranded,had to get bus to railway station ,catch train to milan some 200 km away ,find hotel for the night andget a flight home the following afternoon(�300 out of pocket)