Mar 21, 2018 - 2:59 AM
in reply to Russell1955
Hi Russell, and welcome to MySwissAlps!
I would say so. The Eurail site says "The discount benefits apply during the validity of your Eurail Pass, whereas free passage on trains, buses or ferries is only valid on travel days."
However, you can't reserve seats between Interlaken and the Schilthorn, so there's really no point in buying your tickets this early. They don't sell out.
In any case, it is not a good idea to buy tickets for mountain-top visits until the day before at the earliest, as you need to know what the weather will be like before spending all that money. If the top of the Schilthorn is in the clouds, there won't be any views, and you will have wasted your money.
You can check the webcam before buying your tickets to go up: