If you're using it to balance out a short-ish fruit wine (like me - say you had 8 lbs of elderberries, and needed 12...) you'll probably be fine.
On the other hand, if it smells like grape freshie out of the can... it'll likely smell like that post-ferment.
To give you an idea, I got a recipe for elderberry wine from a family member in England (we have an elderberry in the yard and the yield is insane... too much jam, not enough vino!). His recipe was 12 lbs elderberries, 10 lbs sugar, pectice enzyme and blablabla... well. If you've never tasted an elderberry they're bitter and tannic as all get out. Sooooo... I dropped 2 cans Welch's grape and 2 cans Welch's white grape concentrate in the primary before making up my SG with sugar to about 1.095. It's bubbling away as I write this.
Will it be good? Who knows? It's my first crack at fruit wine of any kind! I'll bulk age it 3 months, bottle it around xmas, try one around Jan. 1, and then try one every 3 months until they're tasting decent.
I only ever learned one thing about beer or wine making: Not quite right? WAIT.