There are more accredited Fellowship positions (ACGME) for Clinical Neurophysiology (CNP - combined EEG/EMG) than for Neuromuscular Medicine (EMG/Neuromuscular). Neuromuscular and Epilepsy fellowships are growing up while Clinical Neurophysiology is/will be shrinking.
To give you an idea, in my program (UTHSCSA), we receive about 30-35 applications for 2 ACGME positions in CNP. Most CNP fellowships do not use a matching program, but select about 10 applicants before or in August for interviews in August-September of the year prior to the start of their fellowship.
There were over 210 CNP fellows about 2-3 years ago, but the number has decreased to about 190 in 2009-10. Keep in mind that there are over 500 Neurology residents in their PGY-4.
In the ACGME site, the accredited programs are:
126 Adult Neurology programs
91 Clinical Neurophysiology programs
23 Neuromuscular medicine programs
Depending upon how competitive you are, one might end up having to apply to all 23 of them or a mixture of CNP and Neuromuscular programs.
Good luck!