The combined effect of caffeine and taurine is the reason that the energy drink is a problem, and why some of the energy drinks are banned in some countries.
Taurine is an amino acid already found in humans, and I can understand why you use it to help with sleep, deficiencies of it can cause anxiety, depression … or even worse, hypothyroidism and kidney failure. And if there is a problem with the synthesis of taurine in our body, this can reduce the liver’s ability to detoxify chemicals. In addition, fungal infections (such as Candida) can produce another amino acid which will sometimes compete with taurine, this of course could theoretically cause a mild to severe deficiency of taurine. If I were going to take it as a supplement, I’d use the liquid form.
As long as you’re not taking the taurine along with caffeine, I can’t see why there would be a problem.