according to my own research, this spell is only available for feral druid which can get combo points. so checking spec and power(energy) should be enough

Dump: value=GetSpellLevelLearned(5221)
[1]=10

It's there for a reason :)

That spell is a default skill for feral druid and before level 10 a Druid can’t change his/her spec to feral; balance is default(?) spec. So if the conditions are met (feral spec and energy as power), we don’t need to register event to trace SPELL_CHANGED event

The reason we're checking for the spell instead of the spec is because of the affinity talents, which lets the druid choose if they want to have feral capabilities or not, while not being feral.

http://www.wowhead.com/spell=202157/feral-affinity

Ah.... my research wasn’t enough. Sorry for bothering you guys. :)