iPhone 6 and iPhone 6s comes with the same display size and resolution. However, iPhone 7 is still not released, but all the leaked information suggest that Apple will keep the display and the resolution same. So these wallpapers are a great fit for these devices. All the wallpapers are of 750 x 1334 pixels resolution.
Update : iPhone 7 has been released now, and it features 750 x 1334 pixels display, this is the same we expected. So these wallpapers are a perfect fit for iPhone 7 as well.