Yes, it is possible to travel across Canada by bus. The west coast includes Victoria, BC, and Vancouver, BC, while the east coast includes Halifax, Nova Scotia. Suppose you are traveling from west to east or vice versa. In that case, it may take longer than expected as you will likely have to change buses in Winnipeg, Manitoba, or Toronto, Ontario, which will add to your travel time. As Canada is a large country, there are land routes and water routes. A large part of Canada is an archipelago. So you can travel by bus to many places if you want, but not everywhere, but you can travel by bus in big cities or big areas.