RFID has various frequency bands ., whereas NFC is restricted to 13.56Mhz which is ISM band worldwide so as far as i know it will work only for tags which falls in this range of frequency i.e., 13.56Mhz
If the phone is NFC capable, and the RFID reader operates at 13.56Mhz, then yes, one can transfer certain types of information between the phone and the RFID reader.