Library and Archives Canada has recently added the images of the passenger lists 1865-1922.
I just found my g-grandmother Ann Jane (Stowell) Pass and her son John Stephen who sailed on the Tunisian, arriving in Quebec on May 15, 1910. Now I'm looking forward to finding out when the rest of the family came.

This site isn't searchable by surname. However, search results can be narrowed down by date, port of arrival, ship name, etc.

This is the link to the search page -- all one line:

http://www.collectionscanada.ca/archivianet/passenger/001045-100.01-e.php?PHPSESSID=9d2f939bab92792fc56606ff70a44d84

OR the 'tinyurl' version:

http://tinyurl.com/ybpdyd

Good luck!