It would be best to have your tax advisor take a look from the perspective of your personal situation.
Members can often (again, check with your tax professional) deduct interest expense and property taxes paid annually.
With most real estate, you could deduct the value of any improvements made to the property from any profit realized at the time of sale. With a timeshare, individual owners, most likely, did not make any improvements that could be deducted. Most components of the dues are related to the actual use of the property (transportation, utilities, housekeeping, MS, maintenance, etc.) and probably cannot be deducted.