The amount of meta required depends on the type of wine (red or white, sweet or dry) and the pH. k-meta is much more effective at a lower pH, so much so that it takes twice the amount of k-meta at 3.4 than it does at 3.1 to achieve the same level of free SO2.
What's important is the level of free SO2 in your wine. I don't measure SO2, but I do measure pH, which is enough to give me a ball-park measurement of what my levels are. There are many charts and graphs available that show the relationship between pH, free molecular SO2 ppm, total SO2 ppm, and the amount of k-meta.
Here is a sulfite calculator
At bottling, dry red wine "should"
contain about 0.5 ppm free molecular SO2, and this can be achieved by usually having 20 to 50 ppm sulfites depending on pH, and white wine should contain 0.8 ppm molecular SO2. Sweet wines can contain 2.0 ppm free SO2 with over 100ppm sulfite.
A little over 100ppm isn't a LOT, but you might be able to taste or smell it depending on the acidity until the levels reduce over time. SO2 usually drops in wine even after bottling; by 10ppm or more within the couple months. So what you might smell very faintly at bottling time may not be there when you open the bottle, especially if you decant and let it "breath" at bit before serving.
I'm not a big believer in using SO2 as a preservative in bottled wine. At bottling time, I add a bit to lower oxidation potential - and levels of free SO2 are probably under 0.3 at the time. Keep in mind that my wine has been stablized (even when using a kit) at least 2 months before bottling. I know a person that uses no sulfite in their wine making process at all, and their big high-tannin/alcohol reds keep for years and continue to improve nicely. SO2 is also a naturally created substance in wine, and even when no meta is added, you'll likely see 6 ppm total sulfites in the bottle.