Reading reviews online and implementing changes on the basis of them is totally different from the real world. If you are CCIE definitely it means that you are certified from CISCO and you have knowledge wherein you cannot compare yourself to a professional guy working in MNC from past 5-6 years (average) and is CCIE as well. 

No institute in the world can guarantee you a job on the basis of money you have paid to them, it all depends on your hard work, the hours you spend with books, routers, switches etc. and how professional you are with your attitude. So, the more dedicatedly you study the more knowledge you get. 

Coming to your question that how Network Bulls offer you a Job Guarantee is that they train you well make you like a processional and make you sit for interviews with different MNCs like BT, CSS Corps etc. now this completely depends on you and your knowledge that how well you crack the interview and yes if you are a CCIE it does makes a difference while you sit for an interview and your salary package also makes a difference.  

I hope the above message clarifies all your doubts.4

CHEERS THANKS !!