I get offers for Delano all the time, but have never received any offers for Vdara or Signature. Do you have to call MGM/Aria and ask, or are they not available(for small players).
I only get back end comps at Vdara. When I called, I was told they were a nongaming hotel and, as such, did not provide upfront offers (at least not at my play level). However, I have received backend comps for Vdara from the host-on-duty at Aria (for play at Aria). I don't know anything about comps at Signature. Hope this helps.