Never heard of a Zebra bee. You do know that there is already a Zebra Pastel that was produced several years ago? Very pretty animal produced by Steve Roussis. Here is a link... http://www.roussisreptiles.com/colle...a_pastels.html
It could be confusing if he were to ever cross that with a spider.
As far as working out the punnet square, remember you're working with three traits. Your goal animal would be homozygous axanthic, homozygous pastel and spider all rolled up into one right? I believe that if you bred a het axanthic pastel with a het axanthic bumblebee you'd have about a 1 in 24 chance of producing what you are looking for.