The payee of a check of a loan they obtain from a bank was the wife. The wife was not in the country when said check was released thus the husband forged her signature, encash said check, and paid the whole proceeds to their existing bank account. Can she be charged with forgery by his wife?

Can the wife file forgery case against husband?

Forgery is a criminal action. If she wants to end the marriage, then she can go to the police and file a complaint.

However, if the money was deposited into a joint account and he left the money there, I don't see what the problem is.

Unless he can prove he had permission to do so ( acting as her agent or had POA)

While the wife could press charges with the DA, if the wife was aware of the payment, and it was put into a joint account or used for the reason the loan was applied for I doubt the DA would follow up if he felt it was more of a issue for divorce court