The new update, version 2.4.1, is not available for everyone just yet. If you have ever downloaded VLC in the past you can grab the new update (with iPhone 6 and iPhone 6 Plus support) by simply heading to your purchased section in the App Store (under the updates tab) and re-downloading the application. Other users will have to wait until it is available in the App Store for all.
The update is slowly rolling out in to select countries first, and is expected to be available to all users soon.
You can install VLC for iOS once it becomes available here.