When you arrive at the airport, get bus No.15 and get-off to green bus terminal.(until 23:00 PM).
Then across the road and wait for blue bus No.6 at the bus stop which is situated outside of the green buss terminal.
At Benitses there are 2 bus stops close to the hotel, one before the Benitses Arches Hotel and one After the hotel.
If you choose to get of at the first one at Potamaki Hotel you need to walk forward 150 meters, if you choose the one after you need to walk backwards 100 meters, look for the hotels sign with the hotels logo.