For foods that are going to be cooked very soon, the issues are cross-contamination of flavours, keeping the knife edge, and other matters of convenience. You really don't have to worry about bacteria.
As regards knife edges and convenience, wooden boards seem preferable to me: they are less aggressive on the knife surface and don't slide around the work surfaces as much as plastics (or, heaven forfend, glass). Personally I avoid woods with too high a silica content because of the effect on knives; this eliminates bamboo; European oak is normally OK if it is used regularly (so not forcibly dried out), but some high-silica soft-wood species might be problematic (I don't know). End grain is softer on knives than side-grain, but (as attested by the practice of just-about every butcher I have visited) the disadvantage of side grain is easily offset with a leather strop.
As regards hygiene, meat sold by butchers is not usually cooked immediately - bacteria have every opportunity to multiply. I believe butchers continuing to use wood provides practical support for the hygienic properties of wood.
So I also prefer to cut foodstuffs that will not subsequently be cooked on a (different) wooden surface. These are the more critical items; however, bacteria tend to be most plentiful on the crops on which is they find it easiest to multiply, so (provided you don't have contamination from foodstuffs that need cookiing to be safe) the risks of cross-contamination tend to be overstated - provided you don't leave prepared foods in a warm environment for long periods.
I would also recommend the following simple experiment to debunk the myth that "sterile plastic is hygienic":
Get some cheese and divide it into four portions with a just-sterilised knife.
Wrap one portion in waxed paper
Place another on a clean wooden cheese-board with a non-touching glass or pottery cover
(you can wrap this in polythene to keep the humidity up if you feel this is fairer)
Wrap another in flexible polythene
Place another on a clean polyethylene chopping board, and provide a similar environment as for the cheese on the wooden board.
Keep all four cheeses in a similar environment (fridge or not-so-cool area).
Check the order in which the cheese becomes inedible.
(The flexible polythene will go off first; although this would not be directly relevant to the rigid polyethylene, it immediately shows that initial sterility is not the be-all and end-all. In addition, the rigid polythethylene will usually be next, followed in no particular order by the other two portions.)