It takes you to a variety of places.
Firstly, where you originally found it. The office of Fontaine Futuristics, the Plasmid’s vial floats confusing a Splicer. Then a locked room behind the Plasmid Theatre, to a scene of a Splicer being chased by said bottle. To outside of Rapture on the sea floor, where a Sea Slug can be spotted.
Finally, to a large dark room, where statues can be seen basking in the glory of Vending Expert 2. Interacting with said Gene Tonic, will transport you back to your original location.