Yes, as no exceptions to the main rulebook requirements for these items are listed in the Blunderbuss special rules. Note however that all enemy models caught in a Blunderbuss unit's 'fire zone" will be hit as normal, regardless of whether or not they belong to a enemy unit which the Blunderbuss unit has line of sight to.
Building an army? Create, validate and share your list with New Recruit, army builder for Warhammer Fantasy Battles (6th definitive edition) and many more games.
Try the builder