>> Our Plan is to base ourselves in Zurich
I am looking at the 4 day Swiss Pass x 2 to cover our sightseeing
1 day to Lucerne/Return
1 day to Jungfraujoch (this will be train to Interlaken via Bern, then to Lauterbrunnen and onto Kleine Scheidegg for Jungfraujoch / Return
1 day in Zurich seeing the city and lake
last day to Rhine Falls and Stein am Rhein.
A 4-day Swiss Travel Pass would cost CHF 259, or CHF 64.75 per day. Using it on the day you spend in Zürich would be a bit of a waste of money. Perhaps you could consider swapping your day in Zürich with your visit to the Rhine Falls and Stein am Rhein, then you could get a 3-day Swiss Travel Pass to cover Luzern, Jungfraujoch and Rhine Falls/Stein am Rhein, and get a ZürichCARD for CHF 24.00 to use in Zürich on the final day. The ZürichCARD will cover a Short Round Trip on the Zürichsee (Lake Zürich), which takes an hour-and-a-half, as well as local transport etc. More information is here:
www.zvv.ch/zvv/en/trav elcards-and-tickets/tickets/other-tickets/zuerichcard.ht ml
>> We will take the train to the airport when we leave the following day; and I do know the pass will not cover this.
That's OK, as it would be a waste of money to use it just to get to the airport. To get to the airport from the main station, you need a 3-Zone ticket for CHF 6.80 second class. You will be travelling in Zones 110 (central Zürich) and the adjacent Zone 121 (where the airport is located), but Zone 110 counts as two zones for fare purposes, so you need a ticket for 3 zones. There is a Zone Map at the link below, and they are also displayed at tram and bus stops:
>> I am also looking at the 2 country (Austrian/Swiss) pass as we will be travelling by train through Austria also; however not sure yet. Would my above itiniery be covered by the 2 country pass?
Coverage in Switzerland is not so good with the Eurail Pass. Some travel that is free with the Swiss Travel Pass is only discounted with the Eurail Pass. You can compare the coverage of both passes, by downloading the coverage maps and seeing what routes are free or discounted with each pass.
As explained in the legend on the maps, red lines are trains, yellow lines are buses, black lines are cable cars, white lines are boats. Solid lines are free, dotted lines are discounted, mostly by 50%, but only 25% in the Jungfrau region. The main differences that are relevant to your plans are reduced coverage with Eurail in the Luzern/Lucern area, and in the Jungfraujoch area.
Swiss Travel Pass
I can't find a way of linking directly to it on the SBB site, which has recently been redesigned, and the file size is too large to upload here. However, if you do the following search in Google, you will be able to download it:
eurail area of validity site:sbb.ch
It will be the first search result, a PDF file called "[PDF]Geltungsbereich Schweiz für Interrail/Eurail Rayon de validité Interrail..."