Yes. If we could, buff Bubble during Void Burn.
No. Not even if we could.
I would say that since the burn is a damage modifier, and the bubble doesn't do direct damage, it doesn't make sense to get a damage boost because it is void burn. As it is now, you get a flat boost to damage /damage resistance because of the weapons/blessings, but I haven't seen anything linking this to the void element specifically. For it to follow that logic, it would then need to get a LESSER modifiers than it has now, if it is a different elemental burn. Now, if the bubble had added void damage to your equipped weapons, it would be a different story. Then it would have to get a damage boost along with all other void damage.
[i]Running double grenade chest piece, you essentially get three grenades if you throw a grenade, then immediately bubble. It's fine the way it is. Blessing and weapons both help in any nightfall.[/i]