I guess you're referring to the answer an admin fills in? No, that's not a problem. In fact, there is no other way in your case. :)
The bonus question feature works like this:
When the closing time of a question has passed and the answer is known, an admin has to go to the bonus question admin page and manually check each answer a user has given for that question.
The answer you give in the admin pages is not used by the plugin to automatically decide if a user answer is right. The answer is only there as a reference for the admin.
The plugin's help page (in the admin) also describes the above functionality. So you can also read it there.