Data Bridge doesn't support MySQLi for the database connectivity portion.
However email and File Upload don't require a database and can be integrated into a MySQLi site. The upgrade is technically from Data Bridge to MySQLi and we generally give a $50 discount. So you could get that discount off your purchase.
Once we release the new version of Data Bridge that includes MySQLi we will be giving people that purchased both a discount equal to the amount they paid for MySQLi Server Behaviors.