Esta has back the Cure Light and Cure Moderate that he used, and not some other stuff that he did not. Esta has an Augury but not a Divination. That seems particularly indicative of spells being refreshed according to their having been used. The Commune is still there, perhaps by way of indicating an outstanding instruction to talk to his god if possible.
Esta received other spells for escaping, defending himself, or enslaving local mortals -- maybe on account of his using the Liberating Command? -- which Esta is probably going to ignore, unless he can think of a way to talk Merrin into accepting a geas without that interfering with their current working relationship. Esta cannot think off the top of his head of a geas that would be worth the relationship risk.