Using the phantom for a TV set up do I need 2 or 3

[ragwo]

Do I need to buy 3 phantoms as left right and center or is left and right enough for watching movies ?

Left and right is more than sufficient. If you want a center channel you'll need a surround receiver with pre out, A/D converters and you'll have to use the speakers in optical direct mode. A bit/lot of extra expense depending on the surround solution you choose if going for LCR. There's a lot of good reading about Phantom and surround here, @njaiswal is the guru.