The Commission has tabled proposals on Denied Boarding, Delay and Cancellation refunds/compensation on cross-border rail travel.
They have also announced their intention to study extending such measures to international bus and maritime transport.
I guess they regard internal bus/rail/maritime traffic as a matter for individual national legislation.
Air transport is different because it operates within a Single Market (under the Third Package, completed in 1997) which does not differentiate between Domestic and Cross-border EU operations.
It would be interesting to see a situation arise where gales in the Channel result in several thousands of passengers having to be provided with hotel accomodation in Folkestone and Dover.