Hi,
International students studying in recognized colleges/universities of Canada atleast a 1 academic year/2 sem/ actual 8 months of study course are eligible for PGWP (Post Grad Work Permit - which allows international students to stay back temporarily and work for up to max. 3 years) as well as OCWP (only those institutions participating in OCWP category, which allows international students to work for part time-20 hours/week after 6 months of actual study in Canada).
After pursuing a 1 year course at GBC, you will be eligible for a 1 year PGWP. To become eligble for a 3 years PGWP, one must complete a recognized full time course of 2 academic years/ 4 semesters/ atleast 16 months of actual study.
On the official CIC website, there is no mentioned rule on PGWP after pursuing two 1 academic year courses.
(
http://www.cic.gc.ca/english/study/work-postgrad-who.asp)
Hence, there's no guarantee of a 3 years PGWP after pursuing two full time separate 1 academic year (2 sem/8 months of actual study) programs provided, each academic year is of atleast 28-30 credits/credit load or more. You may or may not get. You can be assured of a 2 year PGWP though. It really depends on luck. Ultimately it's up to the Visa officer issuing your PGWP.
To know more about other courses and colleges... Here's the list of ALL recognized Canadian educational institutes eligible for OCWP+PGWP, listed according to province:
http://www.cic.gc.ca/english/study/institutions/participants.asp
To know more about studying and working in Canada visit the official CIC website:
http://www.cic.gc.ca/english/study/
To know more about various student immigration programs in Canada for international students (see April 2013 update with official links; mid page 6):
http://www.canadavisa.com/canada-immigration-discussion-board/various-immigration-programmes-for-international-students-in-canada-t100908.75.html
Best of Luck.
***All opinions expressed are purely personal, and pieces of information mentioned are to the best of my knowledge... You should consult other sources too.