Is Glutamine a good supplement to use as well as or instead of Whey Protein?
Also does it have many benifits?

zero benefits. don't waste your time.

all the claims about glutamine helping with muscle growth all stems from research done on terminal cancer patients, AIDS patients, burn victims (like, severe burns over the whole body).

the normal, healthy individual won't get enough benefit from glutamine to balance out the cost of teh supplement. and its a cheap supplement, if that gives you any idea about the lack of benefits you'll see.