I'm not so well versed with mac anymore but
have you used finder to look for say a cakewalk or studio instruments folder ? just a thought and you extracted them etc ?
I mean it's installing it "somewhere" .. maybe it's a case copy / paste to a subfolder off the host sequencer.
as for where the VSTi's are.. it depends on you host.. most will be off a sub folder \vst or say \vstplugins etc.. and maybe you need to do a rescan ? to update your vst list?
you have the mac version , and not the pc version ?
reading from the spec it might be an AU , as well as VST-i ?
a few things to try anyway, contact tech support and they will run you thru a few things