IMHO all later remotes then the BL1000 will work perfectly with the BS2500.
Also, if the system is an early one, then both the BL5000 and the BL7000 will work with it as a two way remote, which is a real fun :)
Please note: The BL2500's RDS system will not transfer the station name to the remote, the only system can do it is the BL7000.