can any one direct me to the artical that covers the total watts per lighting circuit.

Lighting is considered a continuous load.
210.19(A) and 210.20(A) limit continuous loads to 80% circuit capacity, so...

A 120-volt, 20-amp lighting circuit is limited to 1920 watts.
A 277-volt, 20-amp lighting circuit is limited to 4432 watts.
If you are using fluorescent or HID lighting don't forget to add ballast load.

Thanks Redsy!
I tought there was a specific wattage ie(1380watts). My delema is that an architech has specified a single dimmer for two chandeliers with 900 watts each. So before I tell him his design is wrong and we need a dimming module or two seperate dimmers I want to cover my bases.