I took that Alsa bus to VdM mid December 2014 after completing my last camino. The cost was 23 euros and it is advised to reserve the day before. You must show your national passport to book a seat. The bus stops in VdM only on the ave Sa Cameiro. To find the camino walk west along this avenue to the circular junction with the rua Nossa Senora de Fatima. Go up hill on the rua NSdF to rua Jose Maria Goncalves, 10, where the VdM pilgrim albergue of Sao Teotonio (donativo) will be on your left. (Walking from the bus stop to the albergue takes less than 15 minutes.) At the albergue you will see camino markers to lead you across the old international bridge by Eiffel and into Tui, Spain.
Bom Caminho,
MM