that thing looks alot like the weed i had masquerading as a pepper in my garden, needless to say its dead now
its defiantly not Bolivian rainbow im growing Bolivian rainbow this year

keep an eye on it and pinch off a leaf and rub it it hard then smell, if its got a strong pungent smell its a weed

hope im wrong and hope this helps

thanks your friend Joe

That looks an awful lot like a Wonderberry plant to me.

Here is a link that might be useful: Wonderberry