The VIP appartments tower is available with level 50.

Buying an appartment and move an actresss inside improves her experience gain according to the description. Experience is needed for the level up of your girls.

The levels play an important role at the actress acting classes.

Your girls receive a basic experience value while working (amateur and pro films and jobs at the casting tent). Other options for increasing the experience gain bonus are some CC clothes and occupying some buildings at the gang fighting map (North West District).

The appartment is also needed to promote your actress to a starlet or higher rank (option at Big Al). This rank will increase the outcome of your movies. Furthermore money and a certain amount of acting classes (here you are dependant on the level) are needed to promote. From promotion you will receive cups and some temporal bonus effect for your films too.