Bonus is a payment to an employee. In respect of those whose salary exceeds Rs. 21,000, it is a statutory payment, and in respect of others, it is a non-statutory but an employee benefit. Anyway, if the bonus is paid annually, it should be considered a payment or employee benefit, and as such, it shall be included in the CTC.
Normally, bonuses, like other contributions payable by the employer, will be shown after the Gross salary is shown. In order to make it clearer, a salary structure shall contain Basic and VDA as per the minimum wages notification, then other allowances forming part of the salary like HRA, Conveyance allowance, and special allowance, and then gross salary. Bonus, which is paid annually, will come next to Gross salary only. If you have variable incentives, that can also be shown as part of CTC. You can also show the Employer's contributions towards ESI/EPF.