What is your departure time and when is your son's?
I'm seeing trains every half hour at 2 and 32 past the hour from Zurich Hbf.
Since you are getting a Supersaver ticket, I am seeing a slightly different routing for the Zurich-Bern segment, but afterward they should match up. The SBB site will generally show the fastest trains, but you still have the option of taking other trains if you buy a full fare ticket. You, on the other hand, must take the exact trains shown on your ticket with a Supersaver.
For Instance, the Supersaver at 9:06 shows you using IR 2164 to Bern, But the "standard" routing would be with the IC 712 to Bern at 9:32. It is showing that is expected to be very full in 2nd class for that day. The IC 712 is showing a 6 minute cross-platform change, while the IR 2164 is showing a 8 minute change from 3 tracks away.
If he wants to see your exact route, specify via Olten.
The IC train is nonstop between Zurich Hbf and Bern. The IR train makes a few stops on the way.