I would not think that there would be much benefit to aircraft and/or ATC simulators because the exercises carried out on one simulator would, 99 times out of 100, not require the input of the other.
A great deal of pilot training is concerned with flying the aeroplane, handling emergencies, etc. These rarely require ATC input and what little is required can easily be handled by the aircrew instructors. ATC simulators require many "aircraft" so having just one slightly more realistic one available would not justify the expense involved.
Just my feelings - probably hideously wrong!