Are raid boss units and honor stackable?

[Jayson]

If I get to a point in my guild where we can't go any farther, and I go to another guild and help them out will I also get the rewards from them that I already got from my guild?

[GetItFixed]

No, of course not.

[[DW] maretzky]

No, of course not.
As to units - I agree, but not sure about honors...

[Krayt]

Honor is not stackable either