Ifrit warpriest fire affinity question

[Amaranth_]

Fire affinity for the Ifrit read as the following: "Ifrit spellcasters with the Fire domain use their domain powers and spells at +1 caster level".

I am I to do a warpriest, I don't really have domains like a cleric, but I do choose blessing in accordance to my deity's domains. If I choose the fire blessing, does that count as having the fire domain?

And if I were to choose the lavasoul Ifrit, which is the same thing but with the ash domain, since there are no blessings for subdomains I can't choose it, but would simply serving a deity with that domain work?

My guess is that the answer to both is no, but I wanted to make sure.

[Melkiador]

The technical answer is no. You could always ask your DM anyway, as those racials were written before warpriest existed. The gain from it is so very small, so maybe you’d be able to talk him into it.

[Azothath]

correct, it is a technical no.
I think it is worth asking your GM for domain suitability as blessings are tied to domains.
The last two quotes below point that out.

Ifrit
Fire Affinity: Ifrit sorcerers with the elemental (fire) bloodline treat their Charisma scores as 2 points higher for the purposes of all sorcerer spells and class abilities. Ifrit spellcasters with the Fire domain use their domain powers and spells at +1 caster level.

Warpriest class
Blessings (Su): A warpriest’s deity influences his alignment, what magic he can perform, his values, and how others see him. Each warpriest can select two blessings from among those granted by his deity (each deity grants the blessings tied to its domains).
...
If a warpriest also has levels in a class that grants cleric domains, the blessings chosen must match the domains selected by that class. Subject to GM discretion, the warpriest can change his former blessings or domains to make them conform.

[Tim Emrick]

If your GM won't allow it, then there are always alternate racial traits you can swap out fire affinity for, and some of those might be just as useful to a warpriest (like fire in the blood and fire starter).