Bostering matrix - What spells use what affinity?

[Reck]

So it looks like you can pick a bostering matrix that will boost the spells of the affinity that you pick. So astral bostering matrix will boost astral spells

So i'm looking at my spell book to decide which would be the best one for me to get but I don't see anywhere where it tells you which affinity the spell uses. So how can I tell how many spells of each affinity I have?