dxb's analysis holds for the northern counties of England as well, so far as I'm aware. (although Yorkshire people probably say something else, just to be different
)
"Bus Stop" is the place along the route where you flag a bus down; "Bus Station" is the main place where you find buses in large numbers (well - that's the theory rather than the fact
) and where you can change easily (??) from one route to another.
Where I live now, we rarely use "station" by itself, because the trains and the buses are stationed fairly near to each other, and confusion might occur if we didn't specify which.
However, if someone were to say just "station", I, and I think most of my fellow citizens, would assume "train" rather than "bus".
And we usually say "garage" round here, to indicate the place where petrol and diesel may be purchased (usually alongside a full range of confectionary, cut flowers, coal, barbecue charcoal, books, CDs and take-away foods. Not to mention Looto tickets!)
[I meant Lotto, but the typo is so serendipitous that I can't bear to alter it!] 
