Magus of the Moon + Zones

[Hell of a Hat]

My question is if Magus of the Moon (and Blood Moon for that matter) effects nonbasic lands not in play.
The relevant example is Riftstone Portal.

Magus of the Moon Oracle text: Nonbasic lands are Mountains.

Riftstone Portal Oracle text: T Add 1 to your mana pool.
As long as Riftstone Portal is in your graveyard, lands you control have "T Add G or W to your mana pool."

I'm thinking that Magus kills the portal as it doesn't specify in play, but I'd like to make sure.

[Jacob Orlove]

Riftstone Portal is a land card when not in play, not a land.