I've had a few blebs or a while & have never had one rupture, unless I was picking at it (I originally thought it was a pimple!). It could just be a reaction to the laser treatment.
I also had a treatment at the conference and have had some thing happen that I've not had before (mainly bleeding). I was told that that can happen when using a new laser. That being said, I'd email/call them & ask about it. If you email them, I'd try to include a picture of the ruptured "bleb" so they can see what you're talking about.
I hope it's not anything to worry about! Let us know how it goes