Is paying an amount to employees to reduce what we would pay to a company (the owner of the premises) considered bribery, despite our rightful claim to the premises with existing documentation proving it, and our desire for stability? And what is the expiation for it if it is bribery?

If there is a valid contract, the owner is not permitted to terminate it without justification, nor is it obligatory to pay extra money to complete the term. Money can be paid to some workers to reduce the required amount, and this is not a bribe if it is to achieve what is rightful. However, if the right to stay is based on official documents without the owner's consent, it is not permissible to continue except with his permission, and he may request any rent he wishes, and paying money to company employees to reduce the rent is considered a bribe.