Dear Swamy
Whoever it is the Contractor also gots the profit, since he is taking profit, he too eligible to pay the Bonus to it's employees under Normal Practice. Here, the Principal Employer has to ensure whether the Bonus is paid to the Contract Employees or not. In the Wage Pattern itself, the Principal Employer has to make the break up which is inclusive of Bonus. The Bonus Act may talks about the Infancy Period ie, any organisation's age is below 5 years that has been exempted to pay Bonus, but in the same act it is clearly mentioned that, if the Organisation starts to getting Profit within 2 years, then it has to pay the Bonus to its employees from the Origin with Interest, that is why? Most of the Organisations are paying bonus from the starting Budget Year itself.
Since the Contractor is the Contractor to the Principal Employer, the Parent of the Contractor shall be Contract Labour Act (Regulation & Abolition). So you have to pay the Bonus to your Contract Employees, as a Principal Employer, you should ensure with the Contractor, whether the Bonus has been disbursed or not.
Thanks & Regards