I don't live in Tai-Tam but I have a very good friend who does, and I am out there a lot! There are a few different ways you could go. First of all, depending on where you live, (like the Manhattan or Pacific View), they may have a shuttle bus that goes out to central a few times per day. I think it would take about a half hour or so because it wouldn't be making constant stops.
Or you could take a bus to chai wan and then switch to the MTR. The bus ride is 10-15 minutes, and then MTR to Central would be about 30-40 minutes.
Or you could catch the 260 bus, which I think takes about 25 minutes, but it only comes about every 15 minutes or so, so you could be waiting a while for it. Or at the Stanley bus terminal, there are several busses that go into central (6, 6x, and they would probably all take at least 35-40 minutes.
By taxi, it would probably take at least 20 minutes, but it would cost you.
Of course this is all dependent on traffic being good....