If I understand your question, the answer is yes.
If you equip an enchanted shield and a 2H weapon, the shield will not show, but you actually do get the benefits of any enchantment. What you do not get from the shield with this arrangement is any armor rating, improved blocking ability or spellcasting penalty. The spellcasting penalty only really matters to no-armor magic users who might want to use a bow, staff or 2H melee weapon and augment with spells but no armor. So, for 2H users, the shield slot can be used as basically an additional enchanted item slot.
If I understand your question correctly then yes, Shield Enchantments on your armor or clothing always work. Even if you just use your fists. You can tell if a Shield enchanment has effect if your armor points go up in your inventory page.