The landfall ability triggers whenever a land enters the battlefield under your control for any reason. It triggers whenever you play a land, as well as whenever a spell or ability (such as Rampant Growth) causes you to put a land onto the battlefield under your control. It will even trigger when a spell or ability causes another player to put a land onto the battlefield under your control (as can happen with Yavimaya Dryad’s ability, for example).

Admonition Angel’s landfall ability and its last ability are linked. The last ability refers only to cards exiled with its landfall ability.