project structure:
the generator is used to create the tentacles procedurally, you need to apply the geometry nodes becauses currently bones can’t deform geometry made with geoemtry nodes

if you want to retain the procedural nature, you need another mesh to act as the deform object, that the bones work on and then using the surface deform modifier, that bends the procedural mesh, but when you bind the too meshes, then you can’t change the tentacles procedurally anymore, this is how the project is setup, the rig collection contains the deform mesh, and the arms mesh has the procedural tental arms, but there is a bug or mismatch between the binded mesh and the final rendered mesh, so the animation does not show up in the final render only the preview, the work around is to use another mesh in this project called the tentacles in the main collection that uses the arms collection as geometry in another geoemtry nodes setup, you bake the animation that way the final render can render everything as well, this bug usuallly happens with the surface deform modifier

there is a tentacle rig with all constraints setup, that is rigged