Can I open a bank account in Bangkok with a Non O visa if my residence is in another city?

Si vous souhaitez ouvrir un compte a Bangkok, je vous conseille de le faire au head office de la Bangkok Bank sur Silom road.

Le fait de l ouvrir au headoffice facilitera les choses si vous avez des modifications a apporter (num de telephone, adresse) dans une agence d une autre province

I'll preface my response by saying that I'm not living in Thailand, but... from everything I've read in Thailand related groups, I believe that you can open a bank account in any Province in Thailand. The problem though, could be fees and charges from the Bank that you open an account with if you open an account outside your residential Province. I'm obviously not the best person to advise you, but for example, if you opened an account in Bangkok, you would likely pay ATM fees in the Province you live in, even if it's the same Bank.

You mentioned the "agency" said that you can open an account in a different city. Are you referring to an Agent that can help you with such things as Visas, Extension of Stay, opening Bank Accounts? If so, they would be right, but whether they would know, or advise you about any consequences of opening an account outside your 'home' Province, I don't know. Others in the group with experience in these things can correct, or offer further advice on this.