I think you are right about the trigger. It is probably about the book (how to pray the word of God) and it is about you thinking of you all praying together.
The word of God is like a fire: Jeremiah 23:29 Is not my word like as a fire? saith the Lord; and like a hammer that breaketh the rock in pieces?
In the dream though, the lies of the enemies have set the house on fire. It is actually the word of God that needs to set the world on fire. We need to pray the word of God so that it can set our lives on fire and so that the “hammer” (the word of God can break the rock into pieces).
I think it would be a good idea to pray with this family. It appears that there are some negative circumstances in their house. In the dream, you were a “silent” observer although it felt that you were in danger as well. You were experiencing in the dream what they are experiencing in real life so that you can gain some insight into their circumstances.
In the dream it may appear a lot worse than it really is but, there are some lies from the devil “the fire that destroyed the house, there is some dissension (Bob fighting Barb) and there is some self-destruction in this regard (Bob biting his own finger). So Bob may be eating wrong words and that keeps them from going in the right direction in this regard. He is probably declaring negative things instead of the word of God over their lives.
Lookup the meanings of teeth, mouth, and food as well as hand and finger. Bob probably has some problems with all these symbols in his life. Maybe just a bit but still, I think that learning to pray the word of God is very important and this family may really need it, based on the negative symbols in the dream.