In short, YES!
Anyone who registers an an Extra Life Platinum participant on Tiltify is eligible to unlock fundraising power-ups. Please note, however, that if you are registered at extra-life.org AND Tiltify, we cannot combine your totals from each platform. Therefore, you will be recognized as two separate participants.
For example, a Platinum participant who raises $100 on Tiltify and $100 on extra-life.org would unlock two decals ($75 level), and would not have unlocked a t-shirt ($200 level).