The Phil 2 is 84.5db/w/m. In order to hit around 100db @ about 10 feet away you're probably looking at an amp that can deliver around 350w @ 4 ohm. It's possible that 97db peaks or 175w @ 4 ohm - is probably just enough - but I don't think the extra headroom would hurt
I would NOT use Phil 2s for movie watching at reference level as that extra 5db of headroom would require around 1100 watts @ 4 ohm. There are better speakers for movie watching. watching movies a few db below reference level still works, though. Again I would stick to around 7db below reference. Dialogue may be a bit quiet.
The Phil 3 is 82db/w/m so that means those numbers above become 600, 300, and 1900 watts respectively.