<<Once you find it, a B2 is a big slow target.>> - Whereas an aircraft carrier is smaller and faster (and has a smaller RCS)???
I'm sure phalanx & goalkeeper can indeed shoot bombs, but anyone seriously considering attacking any modern ship from the air is probably going to employ the principle of saturating the air defence system - and the B2 carries an awful lot of bombs... It's all a bit of a moot point, but if your scenario now relies on the whole CAG helping, then could the USAF use more than one airframe at a time?
It'd be a good thing to banter about over a couple of pints.
Single Seat, Single Engine, The Only Way To Fly