Accrued bonuses ARE deductible, provided that
1) They are paid within 2.5 months of the next fiscal year, and
2) The person(s) they are payable to are not related parties of the business in question, usually meaning they own less than 50% of the shares.

If they're payable to a related party, ie major shareholder, and that shareholder is a cash-basis taxpayer, then the corporation cannot deduct the accrued amount until the payee recognizes the income.