Could we show the BONUS in Employee's CTC part?

Yesterday in a discussion with my manager we decided to pay the Bonus to our employees, which we were not paying earlier. In question that could we show the bonus in Employee's CTC part. (by putting the remark that bonus will be paid annually.)
Please help me out in this.. If yes, please tell me how to make the salary breakup including bonus part. Please attach any appointment letter for reference.

If what you intend to give is statutory bonus, its percentage depends on the performance of the establishment and the actual amount on the earnings of the employee in the accounting year. Therefore you can not specify any amount in the CTC as bonus but only indicate the range of the probable percentage.

Why we can not show bonus in appointment letter even we are paying on monthly basis.