I had a hard time beating the bot consistently. The strategy that seems to work best is as follows:
Open Silver/Bard. Go for Crypt and Venture. If I hit lower numbers I bought Tunnel or Herbalist. From there I bought mostly Crypts and Ventures, but also throwing in a couple Idols and Tunnels. Eventually this deck hits Dominate. Herbalist is also handy for picking up an extra copper.