My questions are,
1) How can someone trademark a logo that was created by my family in the 1920's?
Simply creating a logo does not provide any trademark rights. Trademark rights come from using a mark in commerce to identify goods and services. If the trademark is not federally registered, then the extent of the trademark would be the geographic area in which the mark is used.
So one theory is that the restaurant was able to use your trademark outside of your geographic area, and was able to register the trademark. In that case you would be the senior user within your geographic area, but not outside of that area.
Another possiblity is that sometime between the 1920s and now, your logo stopped being a viable mark because you were not applying it to goods in commerce. In that case a federally registered mark would be the senior mark even within your geographic area.
The senior (in time) mark holder wins in a contest between confusingly similar marks.
2) Is it still possible for me to use the original label for my wine?
There's no easy answer to that question. If you are the junior mark holder, and your mark is confusingly similar to the restaurant mark, then your use would be infringing.
For one thing, it's not possible to tell from your description just how similar the restaurant mark is to the mark you want to use.
For example:
Does the text dominate relatively inobtrusive artwork, or does the artwork of the logo dominate? Exactly what is shown in the artwork? Is it something that would be otherwise generic or descriptive is used on fruit? What dissimilar elements appear in the two logos.
I'm not looking for you to provide answers or more info. The questions are just to indicate why I'm not giving you a more specific answer.