You will have the following connecting trains from Locarno/Lugano to Bellizona:

13:53pm         Depart Lugano/Locarno on track #
13:53pm         Arrive in Bellizona

And should you miss this train, the next one is at:

13:53pm         Depart Lugano/Locarno on track #
13:53pm         Arrive in Bellizona

Then from Bellinzona to Lucerne, you have seat reservations according to your original vouchers. There are no seat assignments on the boat; 1st class is on the upper deck!

13:53pm         Depart Bellinzona on Wilhelm Tell #CIS2169
13:53pm         Arrive in Lucerne

Please make sure you are at the Bellinzona main train station in time. The train have a sign "Wilhelm Tell Express".

Lunch
The Wilhelm Tell includes lunch. You will get a voucher upon boarding the boat when showing your reservation.