Strange. For the hell of it today I said "siri read my new emails" while driving and it worked
Update: its been working past few days. Spoke to the genius (thats what they call them) rep at my dealership. He was not very familiar with using siri by the steering wheel button to read/write texts or emails.
He said to expect glitches as apple keeps updating its software and bmw takes time to catch up with their updates. He said as a poster above suggested that its probably an apple/bmw software issue.
He said another bmw update is coming and he will notify me when its out. He said I can either bring it in or just use a usb stick to update the software myself.