Wengen is a bit isolated, to help get away from the rest of the world. There is a lot to do there and near there, as Kim's report demonstrates.
Any train trip starts with the 51 minute connection to Interlaken Ost, where you join the mainline network.
The locations you have listed are a on the order of 3 to 4 (or more) hours from Wengen. They are ceratainly worthwhile destinations. Bern is a bit closer and is a nice town with real character. Only 52 minutes from Interlaken Ost.
I agree with Arno that the Glacier express is quite hard to reach, but it can be picked up in Zermatt. (3 + hours away) or Brig, which is 2 hours from Wengen. But, then it takes you further away from Wengen as it goes eastward.
If you are willing to change your sleeping location you can have a second base at Luzern, as one example. Or, you could finish up at Zermatt before going on to Geneva. No single base or set of 2 bases lets you visit all those places with ease. If you really want to see some of them, you will need to pick the day and make a very long day trip. That can be done on the spur of the moment, but should involve an early start. Train reservations are not needed. Just get on and go.
I can't offer anything more than the timetable and a map, plus the links you have seen.
Actually, I can suggest a way to get more information.
The cities all have their own web sites.
And, these two give a lot of information about all parts of Switzerland:
www.myswitzerland.com/ en-us/home.html?gclid=Cj0KEQjwo7auBRCO toqn_s-G7aMBEiQAxArNrFKf3a1cA H9VHcI6yaon2WGYO4SPZyn ZWp7-H3ixAUkaAt498P8HAQ
and , for all non-motorized transportation (look at the header tabs.) -
The timetable is essential, as is a map. www.myswissalps.com/ timetable
Other wise, you are going to trade off some very long rides vs. sleeping close to Wengen.