Bonus Payment and Provident Fund Contributions
You can pay up to 20% as a bonus payment depending on the company's profit (or more, but the terminology used is "ex-gratia" instead of bonus). However, the statutory minimum bonus is 8.33%.
Provident Fund Contributions
In Provident Fund, contributions are deposited based on the wages/salary earned by the employee. According to the Income Tax Act, the bonus is considered part of the employee's salary and is taxable.
"As per the provisions of the Income Tax Act, 1961, the amount of compensation due or received by an employee from their employer in connection with employment shall be taxable as salary in the hands of the employee. Accordingly, the bonus receivable by you shall be taxable in your hands as salary income."
Contributions towards PF are based on the monthly wages/salaries of employees. Employers cannot increase contributions towards PF for just one month.