depending on what you used to back sweeten, you may need to add potassium sorbate (unless you had filtered with a 1 micron or less filter to get rid of all the yeast). If you used a wine conditioner, it will already have some in it, but it's dependant on how much you used.
If you just added sugar, you'll want to add sorbate to prevent fermentation from starting up again, and making corks pop out, or getting sparkling wine.
Also before bottling you'll want to make sure your sulfite levels are high enough to prevent spoilage. If you have a tester, you'll want to have the SO2 levels between 30-50ppm.
K-Meta is potassium metabisulfite, a preservative to prevent your wine going bad. Your kit probably had some in it, labeled as sulfites, camden tablets, or similar in it.
If not, I'd pick some up before you bottle and add according to the instructions with it. It's only a few dollars at a brewing store.
Ok, I'm familar with their Black Currant. One 96 oz can will make 3 gallons of a great wine. Aging my second batch right now. About 3 months into aging Needs to age at least 8-10 months before bottling.
So how long has it been since fermentation finished?
You can age it in bottles but doing so locks your wine in - You cannot adjust it should it need additional sweetening or adjustment of the pH AND more importantly if precipitation occurs, it there for all to see. Aging in bulk keeps the door open for final additions, adjustments or even filtering. One could even claim that, to a small degree the wine is actually exposed to oxidation less in a larger carboy with less air. That last one is cutting it pretty thin but that's about all the reasons I can lay out for you.
Example, I didn't age my first batch of Black Currant long enough (About 6 months I recall) so when I back-sweetened it I thought I had it right. As it turned out I needed less sweetening because it mellowed out so much after a full year from the date the fermentation finished.