For Tam-Tara, I will generally start by using Rouse + Spur and having my pet always attack the add closest to the center. I'll usually start with Miasma to inflict the movement speed debuff, followed up by a Bio. If only 2 have spawned on my side at this point, I'll generally just burn down the first one with Ruin II before switching to the next. If more than 2 have spawned, I'll hit them with a Miasma, Bio, Fester/Energy Drain combo in the order that they come out (if they're close enough, I'll make use of Bane) before going back to the one closest to the center and spamming Ruin II.

I can usually deal with 3 completely on my own but it gets harder from there and depends heavily on how many Aetherflow stacks I have at my disposal. Theoretically, the healer will be helping you with dps during this phase (and the tank helping melee dps) so even if they aren't in Cleric Stance, the two of you should be able to burn through 5 of the adds.