It appears the 'bulk improved finished leather recipe' is bugged. After learning the 'Bulk Finished Leather Recipe' from the skirm bartere I headed over to the theodred rep guy and purchased the 'Bulk improved Finished leather Recipe' but i was unable to learn it. It thinks I already know that recipe.
The regular 'bulk finished recipe' requires glazed leather as it should and teh bulk improved recipe should require raw leather and birch sapwood.
I bugged this in game, but wanted to see if anyone grabbed the bulk imporved recipe before going to the skirm barterer and if it was learnable?
Edit: had improved in stead of bulk refering to skirm camp recipe.
I did it just now after reading your post in reverse order and learned all the bulk forestry recipes just fine. However the Bulk Improved Finished Leather does not appear in my crafting panel after learning it :/
The [Bulk IMPROVED Finished Leather Recipe] from the rep vendor is bugged. It's teaching the normal non-improved Bulk Finished Leather recipe -- the same one learned from the bulk recipe from the skirmish camp -- instead of the improved one.