There are viruses for iOS but they are rare. A developer who presented a proof of concept for an iOS virus was quickly banned from going near the App store. Apple really didn't want anyone to know about it.
You can be sure that with the popularity of iOS devices that hoards of hackers are working hard to exploit any opportunity. Unfortunately Apple didn't plan security into iOS. Likewise Google with Android. Both are franticly working on this issue.
These "bubbles" sound like an excellent vector and I agree with your suspicions.
Generally speaking Safari is not a security conscious browser whereever it is hosted.
Also note that a PC virus can be transmitted via any file so it is quite possible for a Mac or iPhone to become a "Typhoid Mary" so to speak and pass viruses to your PC.