You've posted this under 'Law' and the only 'universal' answer which can be given is that, while you're off sick, you're legally entitled to receive �72.25 per week as Statutory Sick Pay (from the 4th day of sickness onwards).
Anything beyond that amount is determined by any agreement there may be, between you and your employer, in your contract of employment.
So it's impossible to answer your question without access to a copy of your contract. All that can be said is that, unless your contract specifically states that you'll continue to receive the performance bonus, the employer is not legally obliged to pay it to you.
Chris