I had made a wand, and had siphoned mana from the temple. Then, I died, and did not recover the wand from my death spot. Then I made a bookcase, got my grimoire, and then got my arcane bench. I'm now to the step where I need to siphon mana from a temple into the wand. I look at the Grimoire, and it indicates that I'd completed the step.
Technically true, but it feels a little disingenuous to complete a step with a wand that didn't really complete the step.
Perhaps the test should be if there is actually mana in the wand?

I think I'm fine with this the way it is, actually. The point of the requirement is to ensure that players know how to interact with shrines using their wands, so that they can bootstrap themselves. You figured it out on your own, so in your case the requirement was moot.