There is the file with an english text as large as 380K.
$ ls -s /tmp/file.txt
380 /tmp/file.txt

I suppose that deflate should make the text file smaller:
$ ls -s /tmp/file.txt.zip
144 /tmp/file.txt.zip
Yes, that is.

I'm encrypting some text without compression in such a manner:
$ gpg2 --encrypt --armor /tmp/file.txt

and have 196K base64 file:

$ ls -s /tmp/file.asc
196 /tmp/file.txt.asc

After the compression I get much bigger file:

$ gpg2 --compress-algo ZIP -z 9 --encrypt --armor /tmp/file.txt
$ ls -s /tmp/file.txt.asc
208 /tmp/file.txt.asc

So, I've concluded that compression doesn't work.