I apllied for my EAD after the transfer (my case is pending in chicago I got a MSC number for my appliaction)...all EADS and APs go to national center in Missouri. If you apply online there is a place where you have to say which service center your application is pending at. Put the local office name there..and anyway your application gets processed in one central location irrespective of where your case is pending. If you are mailing your application..then you'll have to get the address..some time ago I read on USCIS.gov website about change in adresses for EAD and AP application, I tried loking for it, I couldnt find. If I find it, I'll post it
It tis easier to apply online.