Species tulips you can get away with 3x3; standard type tulips you will not be doing the tulips or yourself a favor with less than 4x6 .
Depending on size of bulb , deeper is better, i.e. four by six will work but six by eight will make for better repeat blooms and six by 10 is as good as it gets.
Bone meal is fine, I still use it as I inherited pounds from my aunt, but dedicated Tulip fertilizers nowadays is better as a large portion of bone-meal just sits there and does nothing but dedicated fertilizer does what it is supposed to do.
