CTC confusion due to Joining bonus

I am not so experienced in corporate so please forgive me if the question is very basic.

As a fresher I joined this company with CTC of 12 lakhs, but 4 lakhs is joining bonus post 2 years... Now without any appraisal in between (expecting one this month but not more than single digit) I am about to complete 2 years

Does this mean my CTC from next year is just 8 lakhs (+ whatever I get as appraisal)

Should I jump before completing 2 years so I get better hike else where ?