You can't can you? just bash?

Just bash.

You can;t power bash with a bow either, just basic bash - though deadly bash does apply to the damage.

More intrestingly, if you bash immediatly after firing an arrow the bash counts as firing a second arrow (Or at the very least, applies the weapon enchantments to the bash), which can be very useful in close quarters if you have a strong enchantment on your bow as you can effectively deal double damage at melee range which helps offset the penalties of using a bow at close quarters; if the attack is a sneak attack the bash also seems to deal the x2/x3 modifier if you arn't fully detected after the shot