Wine tastings are not particularly common in Germany, because stand-alone wine estates are much more rare than in places like the US and Canada. And winter really isn't the peak time of year for this activity anyway. That being said, there is a winery like the kind you have in mind in Eltville am Rhein, near Wiesbaden and an easy car trip from Frankfurt. You may find what you're looking for there.
Of course, if you want all the Glühwein you can imagine, just hit the Christmas Market in Frankfurt!
Jo from Frankfurt can give you some info on events happening in her town during your visit. For places to go in the region, at the risk of stealing Jo's thunder, here are a few hints...
Büdingen, if you want to see an old town that maintains its medieval defensive wall.
Marburg, mainly because it's gorgeous. If you've read The Lord of the Rings, it kind of resembles the description in the book of Minas Tirith (but not in the movie)... meaning, a town that winds around a hill up to castle on top.
Wetzlar, for it's attractive old town.
Braunfels, for it's huge (rebuilt) castle.
Fritzlar, another remarkably well preserved old town, complete with a defensive wall, in a region almost oversaturated with castles.
Eisenach- enough written about this town elsewhere. Bad Hersfeld, on the way to Eisenach from Frankfurt, is also worth a look.
Idstein- nice old town with a castle (are you sensing a general theme yet?)
Hessenpark- open air folk museum just north of Frankfurt. When I last visited about three years ago, it was only half completed. Hopefully they've made some progress since then. Just down the road, you can also visit Saalburg, a reconstructed Roman fort.
Darmstadt, for it's Jügenstil (Art Nouveau) artist colony.
Heidelberg, for...well, being Heidelberg. Enough said.
That's probably enough for now.
