Go back and watch that fight. Bisping was winning nothing. He got destroyed in the first round and the second round was - at best - even till Hendo Hendo'ed him.
Just rewatched it. First round was closer then I remembered, probably Hendo's due to the damage done in first couple minutes. The last 3 minutes of that round and most of the 2nd round up to the KO imo favoured Bisping though. During those times he was landing more shots and controlling the action most of the time where as most of Hendo's punches were glancing blows or missing. That said when Hendo did land they were a fair bit more powerful so did make it close. I now remember thinking that Bisping was going to pull out the decision by winning the last 2 rounds since Hendo had slowed down so much but that didn't come true due to the H-bomb landing.
Imo Bisping has improved his striking noticeably since that fight though. That was over 3 years ago now and Bisping has just looked better and better. I think he is well rounded enough to give Anderson a tough fight(as long as Silva doesn't finish it early) but he will have to get past Belfort first which I think he will but you can never count out Belfort and his boxing.