The same ticket is valid for both busses and trains in canton Zürich.
Price table of the ZVV (traffic organisation Zürich)
Ticket validity is either one year or 30 days. First class tickets aren't worth it because of the higher price, short travel time and busses have only one comfort class anyway.
Tickets are either personal or non-personal. Personal yearly tickets can be replaced if they get lost. Non-personal ones can be loaned out to other people.
There are some special prices for personal 2nd class tickets for passengers under 25 years.
People over 16 can get a Halbtax card for lower prices on both ZVV connections (canton Zürich) and SBB/CFF tickets (whole Switzerland). This was covered in this forum in the past.