I know that wineries are hesitant to plunk down money (even $100 a year) for anything, but if you're at all concerned about the impression you make on visitors to your blog, listen to Rich's advice. Having a Blogspot blog is like having a GeoCities web site or an AOL.com e-mail address - neither communicates care for your brand name.
Ideally, your blog will appear at the URLs
both of which live within the AcmeWinery.com domain. And, of course, your Web site navigation will have a clear link to your blog. If you or your Webmaster can't handle this, get some help. It's not that hard.