Is it permissible to transfer the sponsorship of workers to my wife's commercial registration in exchange for a monthly sum to cover their losses from the rising prices of residency permits, while my wife benefits from this sum?

Sponsorship (Kafalah) is a gratuitous contract (aqd irfaq), and it is not permissible to take payment for it, unless it requires effort, travel, or expense for acquiring documents. In such cases, it is permissible to take a fair wage (ajr al-mithl) without excess.