Bonus: Since you have not replied to the points raised further comments are not being made. Apparently it is not statutory Bonus as per Payment of Bonus Act and is some Retention/Performance bonus etc!
Work Reports; Since work done is to be documented the formats drafted for it and supplied to concerned personnel should be filled and supplied. Each organisation has its own formats. If those have been submitted duly completed in all respects and NO Further information has been sought till date..................and if NOW all of a sudden a need for some information has been felt then the employer has to define/illustrate/explain it with reasons.......................ASAP so that everything can be completed within notice period...........at the most.
However all of this can be as good as fiction since you alone would know what work was to be done/what was done/what has been documented/what has not been documented/what can not be documented at all/what can not be documented within notice period/what is already on records and need not be documented etc...........
If you have not documented the Work Done then it is a misconduct on your part and employer can proceed to impose penalty,punishment.
The employer can also comment on what is specific and measurable!
What are other contract/clauses signed by you e.g. Non Disclosure/Non Compete/Trade Secrets/Confidentiality/IPR etc?
A thorough examination of all docs on record and your inputs is suggested by able labor Law consultant/Service Matters lawyer/Law firm dealing in Labor Law-service Matters and supported by a lawyer dealing in Company Affairs matters!