Package: gzip
Version: 1.2.4-10
bash$ type zgrep
zgrep is /usr/bin/zgrep
bash$ type zegrep
type: zegrep: not found
bash$ grep grep= /usr/bin/zgrep
        *egrep) grep=${EGREP-egrep}     ;;
        *fgrep) grep=${FGREP-fgrep}     ;;
        *)      grep=${GREP-grep}       ;;
             grep=egrep
bash$ 
I think it's reasonable to provide lines for zegrep and zfgrep.  No?
-- 
Raul