While it is not necessary to have a view to make some serious cash on cash return, it's definitely a huge bonus. 

Personally I don't have any of them because I want to pay my taxes today and get all the bonus deprecation now.

Any equity is just a bonus. 

If you plan to do some work on the room in the future then you might have to bring it up to the latest code and would have to pull the permit.A SFR I purchased sometime back also had a bonus room without permits and I did not face any issues. 

Curious.. anyone here interested in credit card signing bonuses?  

With respect to your question, the actual tax rate on the bonus depends on your company's preferred method of bonus withholding. 

My husband has been at his job for 14 months and has received a regular quarterly bonus since he started.  

Do you all recommend using the bonus depreciation status and cost segregation study for multi families or single families if yes why and if not then why?

@Paul Coleman keep in mind some property types will produce more bonus depreciation than others.

For the sake of a standard, let's say we're rating on a long term B & H strategy, looking for cash flow/equity build, any appreciation is a bonus.