Have you been feeding live foods? I've found that live foods and great water quality are the best way to cajole fish into spawning no matter what the species.
If you have had them for a year they have probably spawned already. if you dont have a tank set up special for spawning, i am afraid the eggs will get eaten, maybe this is why you have not seen any fry.
At a year old you should be able to spawn them under the right conditions. Things like conditioning with live foods, water quality/chemistry, & keeping your Tetras in a species tank (a tank with only glolight tetras in it, or maybe glolight tetras & some other docile fish e.g. otocats, cories) would contribute to success considerably.