You can use the IDCAMS ALTER utility to enable batch logging for a VSAM data set that has already been created.
FRLOG(ALL | NONE | REDO | UNDO)
//ALTER1 JOB ...
//STEP1 EXEC PGM=IDCAMS
//SYSPRINT DD SYSOUT=A
//SYSIN DD *
ALTER USER1.BASE1A FRLOG(REDO) -
LOGSTREAMID(CICSMVS.BASE1A)
/*