Need Help with Understanding How to Get Nightjet SBB Discount for Trip from Zurich to Vienna

Your first mistaken is using Rail Europe. Just go to the "official" Swiss Railways www.sbb.ch/en and book your tickets there. Departing Zurich Hbf (main station) to Vienna (Wien Hbf) and put in your dates and times. Continue on through the booking process until it asks you for any discounts you may have. This is where you specify you have a Swiss Travel Pass, and it will correctly calculate your ticket price.

Get off Rail Europe now.
Tickets can be bought at www.sbb.ch/en or www.oebb.at/en
If you buy a nonrefundable ticket, the amount of discount will eliminate any Swiss Travel Pass or half Fare Card discount.

I am planning to buy the Nightjet tickets from the OBB website. I can't seem to confirm anywhere that the "SBB General-Abo 2. Klasse" discount is for the Swiss Travel Pass rather than the Swiss Pass or does it refer to both? There is no "Swiss Travel Pass" discount option. I am concerned that if I claim the wrong discount, I will be penalized when I collect the tickets.

There is no discount with a Swiss Travel Pass for Sparpreise nonrefundable tickets, since the Sparpreis discount is like 1/3 the price of full fare tickets. If you want to pay full price, then the Swiss Travel Pass will give you a small discount.

What are you trying to do? I get the following Sparpreis costs from the www.oebb.at/en site for the July 10 Nightjet.
Seat only 2nd class: 29 EUR
berth in a 6-person couchette: 49 EUR
berth in a 4-person couchette: 59 EUR
berth in a 3-person compartment: 88 EUR
berth in a 2-person compartment: 108 EUR
berth in a 2-person compartment for a single (you take the whole compartment): 158 EUR
berth in a deluxe 2-person compartment: 128 EUR
berth in a 2-person deluxe compartment for a single (you take the whole compartment): 178 EUR

You can fly from Zurich to Vienna for less than most of those train fares. Night trains are horrible, in my opinion. The only reason to take that train is for some views, which you’ll completely miss in the dark. Plus, you’ll arrive exhausted.

And PS - NEVER use RailEurope. It is a travel agency, they don’t operate any trains!

Sam, we want to get 2, deluxe 2-person compartments in September. We are going with the full fare ticket because we are uncomfortable with spending so much on tickets that are not refundable or changeable. When I check the SBB website, as suggested, it looked like the discount is for Swiss Pass holders rather than Swiss Travel Pass holders.

Thanks all for the warning about Rail Europe. I am in the beginning planning stages of our trip Switzerland, Austria, Germany, Greece and Spain so, that is helpful information!

The "Swiss Pass" is the "Swiss Travel Pass". It is the one for tourists.
The Halbtax Abo (Half Fare Card) is for tourists (1 month) or residents (annual).
The General Abo (GA) is an annual pass for residents.

On the Nightjet, most of what you are paying is for the accommodation (room and bed), the actual train fare is a minor cost.

And definitely book through ÖBB or SBB, not a reseller in a different continent.