Hi. Welcome to this board!
I am a college student in california, and can relate to your expectations in raising your VFT's. I, like you, decided to raise my first VFT's in a fish bowl terrarium. I got them in April from Wal-Mart, and have kept them in my room since then. I am using a good quality bulb and I catch house flies to feed them.
I can now see that this was a huge mistake. My VFT's are still alive, but the traps are small and die out quickly after they are fully developed.
My suggestion to you is to grow them in plastic pots by a sunny window, or on a window sill. You need to give them as much sun as possible. My VFT are doing horribly because they do not get natural sunlight. It is true that they will survive with a good bright bulb, but they will not be as nearly impressive as if you grew them out side in full direct sun.
I can no longer repot them in platic pots and place them outside because I am afriad the stress might kill my already weak plants in addition to having Autumn right around the corner. So, I am going to have to wait till next spring to repot them.
If I were you I would be careful using a terrarium. Also, make sure you do more research, the more info you know the better.
Good luck with your VFT's!!!
PS- I found this site really helpful when I was researching VFT's last winter: