I am not a lawyer, but I don't think so. Citizens United didn't rule that money was literally speech, but instead that laws prohibiting the expenditure of money on speech (i.e. a political ad) are impermissible impediments on protected speech. Fraud isn't protected speech, and money laundering isn't speech at all, so I don't think the first amendment comes into play at all. And yes, I don't think constitutional protections would apply to a bank simply refusing to be the medium for a financial transaction.