If the oil is 100% CBD, then they would both be of equal medicinal quality: CBD is CBD. However, cannabis derived CBD is not available to the public due to the very remote possibility of the oil containing amounts of THC that may lead to psychoactive effects, if not prepared properly.
Hemp contains no more than 0.03% THC and thus lacks potential to cause psychoactive effects. 0.03% is equivelent to a ratio of 10,000CBD:3THC, which is about a 3300:1 ratio. However, I would not fret over choosing one over the other.
I hope this helps!