Service conditions-applicability on bonus act

Kindly elaborate the query.

 There seems to be some mismatch between the title of the thread and query in the post too.

>> Bonus is to be paid to an eligible employee by the establishment to which Payment of Bonus Act is applicable.

 Principal Employer will become liable in view of his having the ultimate control over the affairs of the establishment (Contractor). The principle employer may make the provision of Bonus in the wage pattern and may ensure that the bonus is paid the contract employee. Due to the liability the principle employer may ask to set the service conditions with present contractor like in case of previous contractor.

>> However as per: THE PAYMENT OF BONUS ACT, 1965

 32. Act not to apply to certain classes of employees.- Nothing in

this Act shall apply to:

(vi) employees employed through contractors on building operations;

Dear Sir,

1. The earlier contractor from the first year of his operations paid gross salary as a bonus.

2.The contract has been prematurely terminated in the forth year. 

3. Now its the time for  new contractor to pay bonus.

Therefore, on what basis the bonus to be paid ?

Either on the basis of gross salary or as per Act ?

In case of as per act, then what about the "service conditions" clause.

When certain benefit become part of "service condition"

Sir

I further add to above explanation as "all the workers of earlier contractor are working with the new contractor with same designation and place of work".

Thanks