The class and team is defined by the bot's name in the individual bot file.
For Fritzbot ET
The class and team for pre-defined bots is listed in the folder
\fritzbot\docs\ in the file
et_botindex.txt.
For Fritzbot
See the wiki topic
Default_Bot_List. (You will find that these names are largely the same as those in Fritzbot ET).
If you wish to create your own, personal bot, you can read the
file format here. You can also download my
Testbots if you have trouble remembering bot names.