CRB p.300: "You automatically gain a focus pool of 1 Focus Point the first time you gain an ability that gives you a focus spell. [...] Some abilities allow you to increase the Focus Points in your pool beyond 1. Typically, these are feats that give you a new focus spell and increase the number of points in your pool by 1"
I assume, you obtained the Weapon surge through the Deity's Domain class feat? That does not mention getting another focus point.
Compare the 8th level class feat Advanced Deity's Domain, which does.
Hmm, I thought this was wrong. I thought they stated any ability that gave you a focus spell also gave you a focus point... But I'm likely/could be wrong. Also part of the text on page 302:
"If you have multiple abilities that give
you a focus pool, each one adds 1 Focus Point to your pool.
For instance, if you were a cleric with the Domain Initiate
feat, you would have a pool with 1 Focus Point. Let’s say
you then took the champion multiclass archetype and the
Healing Touch feat. Normally, this feat would give you a
focus pool. Since you already have one, it instead increases
your existing pool’s capacity by 1."
This states if you have multiple abilities that give you focus pools, they're addative.
Yes, the Deity's Domain class feat does not give you a focus pool, only another devotion spell to be used with your focus point.
For more points you need to either gain a different ability that gives you a focus pool (usually through archetypes), or a feat that specifically gets you an additional focus point.