this what you had to agree to buy tickets...
 
 By checking this box you represent and warrant that:
      
 
     * You are a United States citizen or permanent resident alien.
 
     * You are making this contribution from your own funds, and not from funds of another.
 
     * You are making this contribution on behalf of yourself as an individual, and not on behalf of a corporation, labor union, federal contractor, bank or other party.
 
     * You are not a federal contractor.
 
     * You are making this contribution on your own personal credit card, and not with a corporate credit card or with a credit card issued to anyone else.
 
     * You are at least 18 years of age.
 
 
 and as eros points out it only applies if you the company, consultant, directly acting as a federal contractor.  employees of contracting firms are allowed to donate...