Ozzie,
Personally, I haven't seen miracle bead grape clusters on wine charms, but here is a website address with directions for some grape cluster earrings:
http://www.eebeads.com/Webzine/99may/5_56_99.htm
The grapes are made using 4mm glass beads, but miracle beads would work as well.
Instead of attaching the grape clusters to an earwire, just attach them to a jump ring and slip them on to the wine ring.
We stock most of the materials you would need for this project...jump rings, miracle beads, colored wire, glass leaves (although ours are different).
Just look at our on-line catalog.
I hope this helps and good luck.
Amy, moderator