Have never been to Bali, but I can comment on SQ1 in First Class as we took this flight a few weeks ago. If you haven't flown Singapore First, you are in for a treat. The flight leaves late from SFO, so the initial meal service is a little abbreviated. We still had a nice dinner and some wonderful wine and champaign (you get a choice between Dom & Krug!) You then get a breakfast (order the dim sum) before landing in Hong Kong. We had a 2 hour layover in HKG which is enough time to do a little shopping and get the blood circulating before the final 4 hours to Singapore.
Where are you staying in Singapore. We spent 3 nights at the Fairmont last week. It was great especially if you can get into the Exec Lounge which serves free Moet & Chandon from 5-8 every night.
Let me know if you have any questions about the flights or Singapore.
John