Black Label
 

I know that if you show your diamond card at Borgata they give you black label but does this work the other way does showing a black card get you diamond ????

Not aware of any current Harrah's status match programs.

But, you can always do DIAD (Diamond in a day) which requires you earn 3,000 Tier (Base) Points in one casino day to qualify for Diamond, instead of the usual 11,000 Tier.

IIRC, there have been some past status match programs in AC @ Harrah's --- though, I can't recall the details. (Trump has also been known to have a status-match program)

I also have to assume that very few [earned] Black Card holders would want to move their play to Harrah's anyway. :p:p F&B @ Borgata beats much of what you will get at Harrah's properties in Atlantic City; and the Borgata lounge beats the Harrah's Diamond Lounges [in Atlantic City].

I guess ill give them a call see I am black label while the perks r good in Borgata I am going to Vegas and that diamond card mean no taxi lines at all Harrahs casinos. While diamond in a day seems like a nice easy thing I will not run 15000 dollars threw machines in one day.

Never hurts to ask.

Though, if it's only access to the front of the cab line (in Vegas) you are concerned with; might be just easier to give a tip instead (that works just as well, and at all Harrah's and non-Harrah's properties ;);) ).

In addition, the cab lines in Vegas have been a little bit less crowded over the past few months, of course, YMMV.