I assume you patched the tank with Bondo or similar?
You really shouldn't have any problems assuming you prepped the surface before applying the Bondo. The vinyl can be pretty sticky, so if the bondo doesn't have a good purchase on the metal, it may peel away when you eventually remove the wrap.
Other than that I'd recommend doing a quick spray over the bondo so that the surface is smoother. Bondo is somewhat spongey and tends to absorb the first layer or two of primer, so I'd play it safe and put a few coats on before applying the vinyl - that way the vinyl peels easier in the long run.
As far as wrapping goes, wrapping bikes is a MASSIVE pain in the ass. It took me about 2-3 weeks of nightly trial/error practicing on parts before I started to get wraps that I was happy with. I ended up using about three times the material I thought I needed since there was so much trial&error when I first started.
There are a few key items that you should be aware of:
1. It isn't always possible to wrap every part with a single seamless sheet. It will take you some time to sort out what the best method of wrapping is, and where/how to hide the seams so they aren't as visible.
2. Vinyl is designed to stretch (obviously), but usually stretching the vinyl past 20-30% of it's original size will begin to affect the finish and color of the vinyl. For example, I had originally selected a satin red color for certain parts of my bike, but as I applied them, I found that the vinyl had an inconsistent finish, becoming glossy where the vinyl was stretched too far. I ended up being forced to use a carbon-fiber-weave vinyl instead as the weave pattern hid the changes in finish a bit better, and the thicker material had a higher tolerance for stretching.
3. Depending on the vinyl you use, the color of the surface it is applied to may impact the appearance of the result. Thinner vinyl (especially when stretched) will have some element of transparency. Be careful when ordering and make sure you use high quality wrap.
4. Every single imperfection will be amplified. Make sure you clean every part thoroughly, and create a clean environment to work in. Even a tiny hair off of your forearm will ruin the finish.
5. Tight corners are your worst enemy; they usually cause wrinkles and folds in the vinyl, and it takes a lot of patience to work those out. In many cases it's not possible to get them all out. If you are a perfectionist like me, they will irritate you to no end. Just do the best you can.
6. Heat is your best friend and worst enemy with vinyl. It's a tricky balance, but I recommend playing it safe and using the heat gun as sparingly as possible.
7. Once the vinyl has been applied, I recommend using a heat gun and going over each part to help seat the vinyl properly. A quick pass over each part, followed by a firm press with a soft rag will help the vinyl form a better bond with the bodywork, which will give it more durability. I also recommend going along the edges on the vinyl with a hot glue gun and creating a seal - the heat of the gule will help the vinyl get a stronger bond, and the added strength of the glue will help prevent it peeling later on.
8. Vinyl never truely "sets". Once you pull your bike out into the sun on a warm day, that vinyl is going to want to shrink and move again. Try to avoid parking your bike in direct sunlight on warm days. Also because of this, I recommend overlapping any seam by at least 1/2", especially where the material is stretched heavily. Otherwise the seams may start to pull apart.
Here's some pics of my work
The Tank wrapped. If you look closely, you can see a seam on the side of the tank, leading from the front edge of the tank grip, and following the curve down to the bottom of the tank. The white part is covered by another body panel, so I didn't bother wrapping it.
A closeup of the Vinyl Material on the tank.
The completed bike
