Nice stoppers!
One of the traps that I find myself falling into is obsessing over finishes. There are a lot of options to choose from, and it's really interesting/fun to test and compare various finishing options.
For those who view turning as a business, the issue of finish has to be treated more pragmatically. Getting hung up on experimenting with exotic finishes can be time consuming, and time spent on testing finishes is time that is not spent producing product for sale.
The basic issue is that the finish has to be attractive, and also able to withstand banging away in a kitchen drawer when the stopper isn't actually being used. Also, it needs to seal the wood - having wine (especially red wine) soak into the wood would spoil the appearance of a finished stopper. And since stoppers are frequently used with wine, the finish needs to be able to impervious to alcohol.
I turn only for fun, so I can afford to spend more time on finishing. For me, the optimum choice is an oil finish - either a commercial wipe-on varnish (I use Minwax), a shop-made long-oil varnish made by combining equal parts of a commercial spar varnish, tung oil and turpentine, or pure tung oil. I wipe on three coats, buffing lightly with either 4/0 steep wool or a gray nylon pad between applications. All three approaches are relatively fast, look good, hold up well, and withstand alcohol.