The thing about working within the BI team, as opposed to being an enterprise-wide DBA or an application developer, is that you may be [unpleasantly] surprised by how little of your time will be spent on the more interesting technical aspects of databases. Do you enjoy two or three stand-up meetings per day? How about sitting through 2 hour long meetings listening to folks ruminate over the definition of "customer"? Another thing about BI is that they tend to use a lot of pre-built ISV databases and logical modeling tools that spit out database designs that are not very well engineered, and despite all your knowledge of SQL Server, you will have little influence over the architecture.
Definitely be careful of this, a lot companies that advertise BI openings really just mean build pretty looking reports.
The job is to implement a reporting platform across all their different software/databases. however, yes it does involve developing pretty reports.