Sorry for chiming in a bit late, Future Combat has grabbed too much attention...
There are no rules for any theatre-specific terrain effects in ViDe, Bocage is mentioned on P.16 as an example for very difficult terrain, and that is also my recommendation.
So Bocage is very difficult terrain and reduces the Movement characteristic by 2”.
If the Bocage you are using allows shooting through is up to you.
Quote from P.18: "As with movement modifying terrain, the opponents should take time to declare the cover effects of each scenery piece on the gaming table before the game begins. Again - the game should not start before it is clear to both players which scenery piece generates a terrain and /or cover effect."
Hope that helps.