I was reading an old Oracle 9 performance tuning book (as you do) and it said that you could not do online rebuilds of bitmap indexes.
I did not have access to an Oracle 9 database so I tried it out in an Oracle 10 one instead and it worked:
SQL> create table tab1
2 (col1 number)
SQL> create bitmap index ind1 on tab1(col1)
SQL> alter index ind1 rebuild online
I then remembered that we had the Oracle 11.2 version of the same book by the same author in the cupboard.
It still claimed that you could not do online rebuilds of bitmap indexes.
Remember, if you read something in a book, be sure to check it yourself.