On the Aare Gorge website that shows prices, you will see this:
SBB RailAway combo offer. If you travel to us by public transport, you
benefit from a reduction on the journey there and back as well as on
the combined ticket Aareschlucht - Reichenbach Falls.
https://aareschlucht.ch/en/info/information#
So you will get a discount if you buy a combined entrance ticket for both the Aare gorge and Reichenbach Falls.
Details on the SBB website regarding this can be found here, including information on how to do this when you already have your train ticket (day pass).
https://www.sbb.ch/en/help-and-contact/products-services/leisure-group-offers/railaway-leisure-travel-offers.html
A RailAway leisure travel offer consists of a public transport ticket
and a leisure activity, such as admission or a day pass for skiing. In
many cases, you benefit from reductions on the additional product when
you travel there with public transport. Reduced leisure travel offers
are also known as RailAway combined offers.
Q. Can I benefit from the discount if I have a GA Travel card or have
already bought my train ticket (eg. Day Pass)?
A. Yes, this is possible. What’s important is that your ticket covers
the whole route for your chosen leisure travel offer. When you
purchase online, please choose ‘Other individual ticket’ under
‘Discount cards’. Please note that our partners providing the
additional product may check the details you have given.
Note: A Saver Day pass is essentially a one day GA ( the travel pass purchased by residents that allows unlimited travel all year round in the GA area of validity). As Sam said, it is not the same as a Swiss Travel Pass.
