你擁有的不是「簽證」,而是work authorization
因為台灣是免簽國,所以你雖然有申請加拿大的work holiday,但你不需要「短期停留簽證」。
哥斯大黎加的規定寫得很清楚,必須是護照上有「簽證的貼紙」才有效
因為台灣是加拿大免簽國,所以你的護照上沒有簽證貼紙,所以你沒有資格免簽進入哥斯大黎加
http://www.costarica-embassy.org/?q=node/72#1
3. If the foreigner has permanent residence, a student visa, a work visa or refugee status in the United States and/or any country of the European Union and Canada, he/she does not need a visa to enter Costa Rica. In addition, he/she must have a passport valid for at least six months from the date of entry into the country and a round trip ticket. Note 1: This type of visa must be stamped in the passport, and must be valid for at least six months.