Routemaster,
I have had a good run on answering your questions..... but I only get half marks for this one!
The penalty is the same for drink driving with ANY motor vehicle.
I am not aware of any statistics that compile information on the type of vehicle involved.
The courts supply us with details of the age and gender of the person disqualified, together with the length of the ban and the reduction that can be gained by attending a course so we have information on those details but we are not supplied with vehicle details.
Thinking back over the years I have been involved with Drink Drive courses, I cannot recollect hardly any client mentioning a motor cycle as their means of transport but 'what were you driving when arrested?' is not a stock question we ask.