What is the ruling on eating at a club restaurant subsidized by revenues that include the sale of alcohol, given that the questioner is unaware of a unified account for these revenues?

There is no blame upon you for what you previously took from the restaurant and the shop, due to your ignorance of their situation. Refraining from dealing with them is a commendable act of piety, but it is not obligatory. Some scholars have permitted dealing with institutions that have mixed capital, citing the Prophet’s (peace be upon him) dealings with the Jews and the Bedouins, while others considered it disliked.