I figured to sum it up best, I would enlist the help of Wikipedia.
Here is what they had to say about it...
"Club 33 is a private club located in the heart of the New Orleans Square section of
Disneyland. Officially maintained as a secret feature of the theme park, the entrance of the club is located next to the Blue Bayou Restaurant at "33 Royal Street" with the entrance recognizable by an ornate address plate with the number 33 engraved on it. When riding Pirates of the Caribbean, just as the ride departs, the Blue Bayou restaurant is visible, but the balconies above it are actually a part of Club 33."
Here is what they say about membership
There are two types of Club 33 membership: corporate and individual. As of February 2008 the current membership levels are Corporate Membership, Limited Corporate Membership, and individual Gold Membership. The Corporate and Limited Corporate Memberships allow for transfer of members, while individual memberships are non-transferable. In the late 1990s, Club 33 offered a lower tier of individual membership, the Silver Membership. However, this level of membership was discontinued. As of June 2007, the membership waiting list was 14 years, and membership interest list was closed to new inquiries as of April/May 2007.
Prior to the closure of the membership interest list, those interested in membership would send a written letter of inquiry to Disney. They would then have received a confirmation letter and information packet. Currently, letters of inquiry are replied to with a letter explaining that the interest list is closed, and no new additions are being made to the list. For those waiting on the list, as memberships open, potential members are informed via a letter of intent from Disney.
Initial fees and annual dues vary by membership.
The Corporate Membership fee is $27,500 plus $6,100 in annual fees. Up to nine associate members can be designated at an annual fee of $4,650 each. Members no longer in the employment of the corporate member's company must surrender the membership cards to Club 33. The corporate member may then designate another member of the company.
The Limited Corporate Membership fee is $13,750 with only one member at an annual fee of $4,650. This entitles the corporation to transfer the membership to another employee whenever necessary.
The Gold Membership is for an individual with a member fee of $10,450 and an annual fee of $3,275. Additional use of a membership card is by spouse only, with reservations accepted only from the cardholder, the spouse, or the cardholder's assistant. The Gold Membership is not transferable.
Members at any level are allowed to make personal reservations 90 days in advance and guest reservations 60 days in advance. Private parties utilizing the entire Club facilities for special occasions such as birthdays, holiday parties, and business functions are available upon member's request with a required minimum number of guests. For an additional fee, members may request any of Disney's costumed characters to appear at the club, as Disney believes "special events [are] always more fun with Mickey or Donald."
The member and one guest (or spouse) receive complimentary admission to Disneyland and Disney's California Adventure at any time whether or not they eat at the Club. Club members and up to nine guests are allowed complimentary admission when dining at the Club. If the member is unable to accompany the guests to Club 33, the Club will arrange admission for them at no charge. Club members receive complimentary parking.
I hoped that helped