I had the same problem and when I looked into the details the only way I figured out was to actually modify the S'rendarr code in order for it to work. The way it is now S'rendarr never even considers spells like Ritual and Blazing Spear as potential buffs to display.

If you, or anyone else, or the S'rendarr authors are interested the changes I made are as follows (user discretion is advised as always when modifying code):

AuraData.lua
Add the following to the alteredAuraIcons array (I've only included rank 4 skills here):

[27175] = [[/esoui/art/icons/ability_templarsun_thrust.dds]],	-- Blazing Spear
[27280] = [[/esoui/art/icons/ability_templar_purifying_ritual.dds]],	-- Ritual of Retribution

AutoControl.lua
Change the line in the Srendarr.OnEffectChanged function from:

unitTag = (unitTag == 'player' or unitTag == 'reticleover') and unitTag or (abilityType == ABILITY_TYPE_AREAEFFECT and GetAbilityDescription(abilityID) ~= '') and 'groundaoe' or nil

to

unitTag = (unitTag == 'player' or unitTag == 'reticleover') and unitTag or (abilityType == ABILITY_TYPE_AREAEFFECT) and 'groundaoe' or nil

Note that as a result of this change you will receive a lot more ground AoEs that you probably don't want so you will need to add them to your blacklist as you see them. There are probably better ways to add effects like Ritual but I didn't spend much time in make them work (a whitelist would probably be a much better idea).

If there are other ground abilities like this that people would like to see in S'rendarr let me know. The reason that buff doesn't appear in S'rendarr is because the ability you cast is not the actual ground ability. The cast ability only spawns a bunch of other abilities, one of which is the important one for the purposes of showing buffs.