Whether they are true or not, it is not the goal of a Buddhist
to pursue them.
Although some people can look at your bazi and it seems to
accurately describe you and predict your future, your future can
still be changed - without the need to purchase expensive fengshui
stuff etc.
What can change is the mind. If a person does away with his bad
habits and adopt good ones, even the Bazi cannot accurately reflect
his personality anymore.
Another interesting thing about these kind of predictions is
that, if you remove the 12 zodiac signs from all the 12
predictions, and you read through the predictions again without
guessing which one is your sign, you will find that they are more
or less suitable to describe you - this is known as the Forer's
effect.
http://en.wikipedia.org/wiki/Forer_effect
If you want to change your life without making the fengshui
master's pockets fat, you can read this free book - it's the Four
lessons of Liao Fan - on how he's fortune was told so accurately in
detailed, and how he changed it.
http://www.buddhanet.net/liaofans.htm