I bought a SW skin about a couple weeks ago, and ever since I put it on my phone, I haven't once thought about putting it back in the case lol (I have the clear Tech21 case). But, for the sake of science........ I just put my case back on, took it off, and repeated it 3 times (inserting the phone differently each time) to see if different areas were bothered at all. My phone has a 5 piece wrap on the back and sides (it was a "custom" wrap to cut down the cost), and my install was a bit poor (3/5 stars I'd say). I also have a small mounting plate on my phone for a mag mount, so this on/off process with the case was not as easy as some might think. I'm also using a thick mounting tape to attach the plate, so my phone's thickest part is quite substantial compared to most....
After being stupid rough with rapid on/off prying, wiggling, not being very careful around the wrap's edges, and almost forcefully snapping the corners into place on occasion: nothing happened to my wrap. No edges were bothered from a lack of care, and none of the skin shifted around on the phone (which I would expect if they used a low quality adhesive).
Now, I will admit that I did take one extra step on the installation that most people won't likely do, and it's a bit different from their instructed final step- I took a lighter to all the edges of the wrap, heated them up a few seconds, then smoothed everything down obsessively with a credit card. The edges became infinitely smoother, and I noticed that the phone was noticeably more comfortable in the hand where my gaps/edges were problematic while wrapping. If you slapped on your wrap without my final step, I would say you're more likely to have an edge catch on your phone case while putting it on and taking it off. Can I quantify the difference, or say much from experience? Nope. However, I would always recommend that step if you want the best install and hand feel.
Now, to directly answer your question: If you're dealing with a single piece back/sides wrap, and you do a proper job wrapping the phone (especially smoothing down your edges with heat and pressure), I see no real potential for ruining the wrap with a phone case. If you aren't very thorough with the edges, I'd say to be a little extra careful removing the case until you're positive the edges are securely attached.
Shortest answer: I don't think you'll have any problems. The adhesive is great, and the edges of their wraps aren't really prone to catches or peeling off (my personal experience).
