你的情况跟我当初公派来加时非常相似,以下只是个人的一点经验(MAYBE NOT APPLICABLE TODAY)
1. If you already obtained your VISA (usually E-1)and just want to apply another VISA for your wife, the chance for your wife's visa approval is close to zero.
2. If you and your wife are going to apply the visa at the same time, your wife has chance, but not much, since your staying time in Canada is too short-only 4 months.