[Covert Bond] does not seem to work with MOA-Companions. MOAs no longer attack and remain cloaked at the very spot during the effect of [covert bond]. I noticed this in the Simulacrum, please feel free to reproduce the bug yourself.
A similar bug has already been fixed regarding the Hound-Companions during Hotfix 34.0.2. Hence I assume that fixing MOAs should be very similar.
Kind regards