Do bubbles prevent Saurfang from gaining Blood Power?
Not anymore. Sadly. 
Absorbs such as Power Word: Shield no longer prevent Blood Power from being gained when damage is dealt by Saurfang. Casting Power Word: Shield is not a bad thing to do as the ability will absorb the damage dealt. This was an intentional 3.3.2 change. We also removed the ability to knockback the Blood Beasts off the platform and the removed of Blood Power gain from Mark of the Fallen Champion damage. We unfortunately missed getting these changes into the patch notes.
The original post about this can be found here.
But to answer your question, yes if you are spec’d Dsicipline.
In the 10 man, we had three heals: me, shammy, and a druid. They healed and I bubbled the entire raid over and over and over again. The good thing is some people were already bubbled when Blood Boil hit them. Even when I got it, I could see that the bubble was absorbing most of the damage from Saurfang. I tried to keep an eye on his Blood Power. He topped out around 65 Blood Power when he died, and he never dropped a mark! Not a one! So, yes, it works. It makes the fight much easier!
My suggestion is- and I will share it with my guild for the 25-man- is to have your preist(s) go disc just for this fight and watch what happens.
Find more answers to our Frequently “Googled” Questions here.
Hugs. .-= Sephrenia´s last blog ..Whether you think that you can, or...
I spent a lot of time researching Saurfang this weekend and found that it appears that the dynamic of priest shields in the fight was changed in Patch 3.3.2. This is based on the review of our logs and also Blizzard quotes I found in the WOW forums. The two biggest changes are that the Shields no longer prevent Blood Power from being gained; however, the Mark no longer causes Blood Power. I will now be trying the fight as Holy next time to see if it is easier or harder to heal in that capacity.
I forgot this question was on here and that I would need to change it. LOL TY.