I had that debate as well, I lost and they do accept the matricula card, but we additionally must have another form of ID. The matricula cannot be used alone. Maybe suggest that?
The government put out for comment whether there should be documents that could not be used. They determined that it was best to leave it up to the institutions whether to accept documents like the matricula consular or not. Here is the document from the Federal Register. [url=http://www.fincen.gov/statutes_regs/frn/pdf/326_disposition_of_comments.pdf]Federal Register
We're having a debate about whether or not to accept the matricula card as a valid form of ID for opening account. I know that some banks do accept matricula card while others don't. I googled but can't find a definitive answer whether or not the US government finds the matricula card acceptable.