Both. It's "whenever", so it goes off each time any of the triggers happen. You could even drop it and grab two lands, attack next
turn for another two, then
flicker it with
Restoration Angel after combat and grab
another two when he enters the battlefield
again.
You should also consider that the second trigger is "whenever
Primeval Titan attacks..." which triggers when you
declare attackers. You will get the lands right away, before your opponent declares blockers. In response to that, or in response to the declaration of blockers, you could
flash Restoration Angel down to
flicker the
Primeval Titan (which removes him from combat) and get another two lands, before combat damage even happens.