First off, it would be appreciated if you used CODE bbcode markup to encase your code so it is easy to differentiate. An example result should look like the following...
FS1:/home/scripts # symrdf query -g MYDG | grep DEV001 | grep -vq Synchronized && symrdf query -g MYDG | grep -e MYDG -e DEV001
On to your issue when you execute grep -vq you're hiding the output of grep and the "&&" portion of that command is bash logic for running a command after successful exit of the previous command list.
That being said if you extract the command which is giving you output then the following is its own command by itself.
symrdf query -g MYDG | grep -e MYDG -e DEV001
Notice that you're not specifying to omit anything. You're just searching for all lines which contain the string MYDG or DEV001. You should modify that to include something like...
symrdf query -g MYDG | grep -v Synchronized | grep -e MYDG -e DEV001
I also think that your script will always produce undesirable results because you're not cleaning up the output of the previous command (getting rid of the display clutter) showing just what you want. In any case, there's a start for you to be on your way to getting what you want.