Since I have summoning working now, I've sorted out the various "sommoning type" spells:
Call Heaven's Guard (Heavenly Cycles)
Summon Abyssal Creatures (Sorcery)
Reanimate Dead (Reanimation) - just Zombies for now; they are hostile to everyone including you
Raise Dead (Necromancy) as above but they are under your control
Call Animals (Animal Lore policy) - wolves and lions now
Conjure Monster (Conjuring) - Picks the best monster from a list based on your spell mod. But right now it is only Giant Spider
Call Angel (Celestial Knowledge)
Summon Demon (Summoning)
Call Tree-Ent (Forest Dominion policy)
Call Archangel (Divine Intervention)
Summon Archdemon (Breach)
Call Major Spirit (Pantheism finisher)
The last three essentially call gods or god-like beings into physical form.
Major Spirits are the same gods that pantheistic civs interact with as "hidden" minor civs, giving quests and so on. They're mostly already named in the phase II game manual, e.g., for Cult of Leaves you have Fagus, Abellio, Buxenus, Robor, Abnoab, Arduinna (I think 35 or so are in the game now). You have to have a temple to the god and a super high relationship with them; calling the god has a cost in relationship points.
On the Theistic side, the archangels and archdemons are now named in the game manual (at some point in the distant future this will all get into the civilopedia). So these are the individuals you can call/summon. Here's are the new manual sections that name them:
In the hierarchy of Heaven there exists below Azzandara exactly twelve archangels and an uncounted number of angels and heaven's guard. All of these lesser beings can be called to assist Azzandara followers through divine spells, although an archangel can be called only once. In order from lowest to greatest, the twelve archangels are Zam, archangel of soil and the land; Drvaspa, archangel of cattle and animal domestication, Tishtrya, archangel of life-bringing rainfall and fertility; Ashi, archangel of material and spiritual recompense ("good reward"); Anahita ("The Immaculate One"), archangel of healing and wisdom; Tushnamaiti, archangel of silent meditation; Iža, archangel of sacrifice; Ātar, archangel of holy fire; Verethragna, archangel of victory; Rashnu, archangel of justice; Sraosha, archangel of obedience; and Mithra, archangel of covenants, oaths and truth.
In the hierarchy of the Abyss there exists below Ahriman exactly eight archdemons and an uncounted number of demons and abyssal creatures. All of these lesser beings can be summoned by either Ahriman followers or practitioners of Sorcery (summoning spells have both divine and arcane forms). An archdemon can be summoned only once. In order from lowest to greatest, the eight archdemons are Zauri, archdemon of poison and assassins; Gannag Menog (the "Stinking Spirit"), archdemon of rotting corpses; Aka Manah, archdemon of vile thoughts; Taurvi, archdemon of unquenchable thirst; Naonghaithya, archdemon of discontentment; Indar, archdemon of indecision (the "frozen mind"); Saurva, archdemon of oppression, unlawfulness, and the production of want; and Aeshma, archdemon of wrath.
The archangels and archdemons have some relationship to the seven "good" and nine "evil" temples that Devouts can build. For Aŋra, it's more or less a one-to-one relationship with temples I - VIII dedicated to the eight archdemons (in order above) and temple IX to Ahriman. It's a bit more complicated for the seven Azzandarayasna temples: they are dedicated to the Six Aspects of Creation (I - VI) and That Which Exists Outside of Creation (VII).