"Club" seats at the TD Garden are basically purchased for the year by season ticket holders (big the US with basketball and hockey being played in the same arena). These seats are offered to the season ticket holders first and whatever is left over is released to the public. Inventory won't be known by Ticketmaster until the local box office gives them the remaining inventory.
The LOC has already sold quite a few All Event seats, which diminishes the inventory greatly. I know we are very close to selling out the Ladies final already and expect that will happen within the first hour of the public sales.
If you can reach a real person at the box office by phone, that may be the best way to purchase multi-event tickets.