Thats hard to answer because it would depend on the quality of glass/thickness of the vase, it might not be pyrex, but it might be tempered or not.
It might work, it might work for ever, it might explode after 2 weeks, the fact is if your running any HID lighting theres gonna be a lot of heat, and when the light comes off if your fans are running the glass will cool fast and if its cheap glass it will shatter.