Нигде, это не лодка. По идее с билетом должен идти ваучер. Это вот что Вы купили:
Buy an all-in CP + Yellow Bus ticket, composed of a return train journey and a voucher for a Yellow Bus circuit of your choice by bus, tram or boat in Lisbon or by bus in Oporto, Coimbra, Braga or Guimarães. The total price includes the 15% discount on the tourist circuit you choose.
On sale from
The all-in ticket is available from CP ticket offices or the Online ticket office and Customer Care Line*.
* Available for Alfa Pendular, Intercidades and Regional trains as an add-on to the previous services.
The Yellow Bus voucher must be exchanged for a ticket on the bus, tram or boat of your choice. The ticket is valid for 24 hours in Lisbon, Oporto, Coimbra, Braga and Guimarães. It is valid for 1 or 2 days on the Oporto circuit.
You can also buy your Yellow Bus separately and still get your 10% discount if you show your train ticket on board the bus or tram.
Valid for return train tickets to or from any of the cities mentioned.
Cannot be used in conjunction with any other discounts or special offers.
Validity - 3 days before or after the train journey.
Circuits
Lisbon: Tagus Tour, Olissipo Tour, Hill Tramcar Tour and Yellow Boat Tour
Oporto: Porto Vintage (includes Ancient Oporto and Porto of the Castles tours) 1 and 2 days
Coimbra: Funtastic Coimbra
Braga: Braga and Bom Jesus Tour
Guimarães: Guimarães Tour
Check prices here for the all-in-one CP + Yellow Bus ticket.
More details about the circuits, particularly the days they run and the programme here.
То есть ваучер Yellow Bus вместе с билетом нужно обменять в автобусе, трамвае или прогулочном катере (не знаю как точно перевести) в зависимости от маршрута, собственно на билет.