Andre controls Wheel of Sun and Moon and Grenzo, Dungeon Warden.
He uses the ability of Grenzo, Dungeon Warden. The bottom card is an Ornithopter.
Where will the Ornithopter end up? Bottom of library again or battlefield?

Assuming Andre is the enchanted player, it will be on bottom of the library.

An effect that moves a card from zone A to B and then moves it again can only move it the second time if the card went to a public zone (not necessarily B, it can be put elsewhere due to replacement effects). Here, it's put into a private zone, so the effect can't move it out of there.

Daniel Kitachewsky
L4, Paris, France
Rules NetRep