Here is what reply I got from Red Bull UK:
“Thanks for getting in touch about this.
I can 100% confirm that Red Bull contains no animal derivatives and that all ingredients are synthetically produced and are not extracted from any animal source (so the bull’s urine myth is completely untrue!)
Taurine is a conditionally essential amino acid, which naturally occurs in the body of all mammals (including humans.) However, the Taurine that is contained in Red Bull is synthetically produced and contains no animal extracts or derivatives, therefore it is suitable for consumption by
vegetarians and vegans as well as being certified as Halal and Kosher by the relevant federations.
The wikipedia information relates to Taurine in general and the majority of the information (particularly about where it comes from) does not apply to the Taurine in Red Bull.
Red Bull UK”