does the Shogun 2 collection on HB in tier 2 include the addon and all dlc?

No, Fall of the Samurai and its dlc's aren't included.

ok thx for the info, that is good to know, because I have one left and I need to know what I have if anyone should be interested.

From another thread: (clicky)

Total War: Shogun 2 Collection - Includes 8 items: Total War: SHOGUN 2, Total War: SHOGUN 2 - Sengoku Jidai Unit Pack, Total War: SHOGUN 2 - The Hattori Clan Pack, Total War: SHOGUN 2 - The Ikko Ikki Clan Pack, Total War: SHOGUN 2: Saints and Heroes Unit Pack, Total War: SHOGUN 2 – Otomo Clan Pack DLC, Total War: SHOGUN 2 - Dragon War Battle Pack, Total War: SHOGUN 2 - Rise of the Samurai Campaign

If by add-on you mean Fall of the Samurai, it's not included.

Thx for the details.