Alan,
I once made a small walnut oval topped table and finished it with Behlens Rockhard Table Varnish. It is an alkyd short-oil varnish and buffs out fairly well. Much better than a typical polyurethane varnish, as Howard mentions. I brushed on several coats of the varnish, sanding lightly between coats, and put a cover over the top to keep dust from landing on it. It worked pretty well although small nibs will be cut off during the sanding/buffing process. Since a fair amount of finish will be removed during sanding, you should make sure that the last coat is relatively thick. Otherwise, you might sand through the top layer to reveal inter-layer witness lines. If you do, about the only solution that I found to work was to apply another coat of varnish. This is one disadvantage of using a liquid (like water) as a sanding lubricant - it hides the fact that you have sanded through the top layer. Unfortunately, I learned this lesson three times! Dry sanding is messier and uses more sandpaper but it is easier to see where you are. I waited more than three weeks before starting the sanding/buffing process. The harder the varnish, the easier it will be to achieve a high gloss finish. Get the top layer as flat as possible, going through at least 600 grit paper, before starting buffing. I used a buffer as you are with auto polishing and buffing compounds. Howard warns against staying in one spot too long to keep from melting the finish. Good advice! If you melt an area it is a royal pain in the *** to sand it out - all the while getting closer to a possible sand-through of the top layer. I would also advise you to always hold the buffer so that the buffing pad is moving OFF of the edge and do not apply too much pressure near the edge. Do not have it rotating INTO the edge or it will be difficult to not buff through the finish on the edge, where it is the thinnest. This was a great learning experience (taking about four months for the finish work alone!) and the table turned out really nice. Hope yours tuns out as well - good luck.
Dave