If someone (trained) can do a one-armed BB snatch, can they (untrained) do a regular BB snatch? What about vice versa? The pull-up or push-up used as an example here would be painfully obvious. Pistols vs. air squats are another one--anyone who can do a pistol can probably do quality air squats, while being good at air squats does not imply anything about being competent at pistols.
My guess is, due to things like balance requirements (assuming equal strength levels), that unilateral would transfer to bilateral better than the other way around.