Heather,
There are two locations for
Bibbidi Bobbidi Boutique, and just the one for
Pirate's League. Lets consider each separately.
The easy option is if your Bibbidi Bobbidi Boutique reservation is for the one in the Magic Kingdom, in Cinderella Castle. Since Pirate's League is also in the Magic Kingdom, over in Adventureland attached to the Pirates of the Caribbean attraction, all you need to do is walk from one to the other. That is a 5 minute walk, 10 if you are dealing with big crowds.
The other option is if you are at the original Bibbidi Bobbidi Boutique which is within the World of Disney Store at Downtown Disney. In this case you need to take the bus from Downtown Disney to any of the Monorail resorts (the Contemporary, Grand Floridian Resort, or Polynesian), then monorail to the park. Sometimes you can get a direct bus from the Magic Kingdom to Downtown Disney, but not always, so I would suggest this is a more reliable route. In this case you need to plan about an hour of transportation time, to be safe.
I hope that this helps?
Have a magical vacation!