It was something she triggered not something she consciously generated and controlled. It was the spillover of House of M through a tear in a dimensional wall.
Chaos Wave is Wanda's power not just some side effect and even if you do think that, it was Wanda herself that stopped it and reversed everything with ease when she was done messing around with reality.
HOM Wanda is a true Omniversal power.
Saying that this version of Spectre is basically the presence right? Or merged with aspect of it? So depends if that means he had full power of presence or not.
Side not, IIRC power of chaos Wave(so Wanda) was stated to be a possible threat to the creator (TOAA). Only person/power ever to have that on there resume within Marvel comics. Lol, could.just be hyperbole though😉