<<" Can I ask - if we fly to Zurich do we take a train to wengen or grindelwald? Thanks so much.">>
Not only can, but may. ;-)
The answer is yes.
Please refer to the timetable link I gave you in my first post.
You will see something like the attached screen grab image.
Here are a few things to look for:
1.- I expanded the first journey by clicking on the "+" at the left.
2.- Once you have done that, you get a lot of detail about train services ( e.g., restaurant or mini-bar to the right), connections, connection times (they seem short, but they will be fine if you move quickly with your luggage. From track 5 to track 6, for some of the train connections (but not all) at Bern is on the same platform. This station map from the SBB website shows the track numbers if you zoom in.
I believe that all trains pass through Zurich HB (main station) in some cases, you may have to change there for Bern. In other cases, the train stops at Zürich HB, but continues to Bern. expand each journey in the timetable and you can see that.
plans.trafimage.ch/ber n#?lang=en&layer=bern_inn enplan&x=600112&y=1996 75&r=0.12
3.- in the fine print, after you have selected your journey and expanded it, you can chose a map.
In addition, the map I would use for general views of Switzerland - railways, highways, cities, accommodations, etc, is:
for general overviews, and, if you work the options menus, you can zoom in far enough after selecting "Traffic" in the Points of Interest" and the icons for the train stations, etc., will show up. Mouse over them and you get abbreviated transport schedules to/from that station.
If you spend some time with that map, you'll see how the train gets you there via Bern
I picked a date at random for that screen grab. I chose early September, because I think it is the best time. Since your grandson is probably in school then, you might be looking at July? August gets pretty crowded, since so many Europeans are on vacation then.
it would be helpful to know your dates, because some things have seasonal gaps in service. Unlikely in the summer, but, for example, Swiss National Day is August 1, and lots of stores and restaurants close then.
Finally, although I find topo maps most useful fro hiking, the various panoramic maps of the Jungfrau Region found with a Google search may help you visualize the lay of the land better.
www.google.com/search?q=Panoramic+map+of+the +Jungfrau+region&ie=ut f-8&oe=utf-8