Oh, I believe in redundancy.

When I bond a swimming pool, there's a bonding lug on the inside and the outside of the stainless light niche. I bond #6 bare solid copper from the outer lug to the rebar cage, and a green #6 stranded from the inner lug to the light junction box ground runner. The pool rebar cage is bonded to the steel motor sheel and then to the panel ground busbar. The handrail and grabrail anchors are likewise bonded to the pool rebar. NEC250-50-2.

I go to all this trouble because if the motor has a serious problem and puts current on the pool water via it's case, all metal at the pool will be at almost exactly the same voltage potential and there will be no current flow. Any minor variance is due to differing resistances in the various current paths.

And if you check the price of copper wire, it might NOT be cheaper to wire the garage....