パス料金だけ（等級は無関係）

PASSES, PRM's ACCOMPANYING, FIP 77.00

2nd class passes are also valid in Grand Class and Club Class, providing the passenger pays
for the corresponding cabin service.
Pass holders can purchase your ticket at Stations or on Rail Europe website.

elipsosサイトの関係しそうな箇所だけ抜粋。
ADVANTAGES
- You have a first o second class pass? Elipsos Trenhotel allows you to benefit of your pass for travelling
with the level of confort you choose, in any of the Trenhotel classes, no matter whether your pass is first o second class.
- Benefit of the pass advantages even in your own country, no need to reach the border*