Is it permissible to pay incentive bonuses to a committee charged with providing work supplies for an oil refinery, given that the work was successfully completed within the stipulated conditions and time?

You are only entitled to what you have been authorized to receive by the responsible authority in your workplace. It is not permissible to take an incentive bonus without their permission. The money or tools under your possession are a trust that must be preserved, and it is necessary to return any excess allocated for work, for Allah Almighty says: "Indeed, Allah commands you to render trusts to whom they are due" [Quran 4:58], and in the Hadith: "There are four characteristics which, if found in a person, make him a pure hypocrite: when he is entrusted, he betrays."