Nov 10, 2015 - 2:05 PM
I don't know, that's up to the Swiss Railways and the Jungfrau Railways to decide. By the way, the lower sections (Interlaken to Wengen or Grindelwald) are free with a Swiss Travel Pass and 50% discounted with a Swiss Half Fare Card.
Ultimately, what matters is your overall travel expenses. You can compare passes as explained here.
Last modified on Nov 10, 2015 - 2:08 PM by Arno