Is it permissible to dispose of an amount of 4500 Saudi riyals, disbursed as a committee bonus to someone who did not perform any work therein, or must it be distributed to the needy or used for the development of the department?

If you were disbursed a sum as compensation for work on committees in which you did not participate, you are obligated to return it to the disbursing entity and explain the situation to them. If they permit you to benefit from it, then it is permissible; otherwise, it is obligatory to return it. It is not permissible to give it as charity to the poor as long as you are able to return it to the rightful entity. However, if you had joined the committees and were ready to work but no work was assigned to you, then it is permissible for you to benefit from the remuneration; because it becomes due merely by being enabled [to work]. It is stated in the Fiqh Encyclopedia that the wage becomes established if the hirer has utilized the benefits or if the period has passed without any impediment.