What can be used as a wrapper with minimum taste?
It's not entirely clear if this needs to be cooked after being wrapped. If you can cook it beforehand, and you really want something that has no taste at all, then you can't do much better than the technique Adria uses his tomato and black olive ravioli, which is basically to create paper-thin sheets of gelled agar and gellan, cut them into circles, and wrap. Of course the technique makes it trivially easy to adapt to other shapes and sizes. If you really want them totally sealed, a torch or even a smear of very hot water should do the trick, it'll gel again as it cools.

If this needs to actually be baked or fried, then I'd go for dumpling wrappers or gyoza wrappers, which are just circular versions of spring roll skins. This is exactly the application they exist for, and there are various kinds of rice-based skins that are so thin, they're actually translucent:



It goes without saying that white rice is pretty bland and won't add much flavour of its own.

The Cook's Thesaurus also has a long page on wrappers; if the above don't work, maybe one of their other suggestions will suit your fancy.