it is not clear whether you ara talking of bonus under the Payment of Bonus Act 1965. It appears youare talking of bonus that is being paid on the occassion of Diwali which is like a customary bonus. There are two ways of lookinag at the problem.
1) if there is an agreement with the employees on the apyment of Diwali bonus, that agreement must have stipulated the items of salary which shall be taken into account for computing bonus. In that event you can follow the terms of agreement.
2) Secondly, in the absence of such an agreement, the custom can be relied. Find out what are the items of salry that are being considered for computing bonus since it's inception. Yiou can follow them.
However so far bonus under the Bonus Act is concerned, normally the following items of salary are included.
1) basic pay
3) Free food allowance or the value of free food suplied.
The following items of payments are normally excluded.
1) Any allowance which is for the time being paid(temporarily paid)
2)value of any housing accomodation, or any amenity as light etc, supplied.
3) Travelling concession
4) contributions to P.F and pension
5) retrench ment compensation
6) any bonus like incentive bonus etc.
7) any commission
8) any O.T wages
consultant in Hr and Labour Laws
9th December 2010 From India, Mumbai