My dealer used BMW 15W-50 synthetic at the 600 mile service on my '12 RT. I asked many questions then determined if this is due to a change that BMW has made I will go along with it. If for no other reason to ensure I don't have challenges for warranty claims down the road.
The dealer appeared to be flexible and would have used dino if I preferred. I am at about 3k miles now and the bike has used almost a full quart since the 600 mile service. I have been keeping impeccable records and will present them to the dealer at the next service point, although I do plan on performing the service on my own.
I hope this helps.