Mike it was a wording issue. When you say a Non O because of marriage that normally refers to the Visa or extension you get when married to a Thai. You are trying to get a Non O because you are a dependent of a foreigner legally working here with a Non B Visa. That said I have never heard of someone in your situation being told you had to have a bank account.
well I can only tell you what happened. If you want to disregard it because four of us (me and three Thais) didn't ask the supervisors we spoke with, who both confirmed the rule, ok. But seeing as that four different people at MOL told us the same thing I have to believe it's correct