Is it permissible to benefit from financial aid provided by a non-Muslim government if the source of these funds is taxes imposed on alcohol, cigarette, and other forbidden companies?

Funds collected as taxes for committing prohibited acts cannot be returned to their owners, because returning them would aid them in their wrongdoing. Rather, the way to handle these funds is to donate them to those who are deserving. Ibn al-Qayyim mentioned that what is seized with the payer's consent and after he has received his forbidden compensation—such as someone who exchanged for wine, or a pig, or fornication—the compensation does not have to be returned to the payer. This is because he willingly surrendered it and received his forbidden compensation, so he should not combine receiving the compensation and having the compensated item, thereby reclaiming his money. Therefore, it is permissible to take these funds and spend them on the deserving among the poor and needy Muslims.