I know for Imbue itself the Public & Queens Forge give thier own bonuses.
I also know that a Gargoyle has bonus to Imbue itself too.
What is not stated anywhere is if this applies to unravelling.
All articles I have read sofar only imply the bonuses apply to Imbuing.
As I cannot unravel the exact same loot twice, it is hard for me to verify for myself that any Race or Forge bonuses apply to unravel, making it unclear if it matters at all where you unravel loot.