I purchased one bundle, if I purchase another will that give me more blocks to expand my current midday estate house which is limited in size to 250 blocks? I don't want to build a new house just improve the one I have.
If you purchase additional blocks, either through an additional bundle or through a build-a-castle medieval set pack, it does not raise the amount of bonus blocks you can have on an inside or outside area.
However, if you have used 250 blocks to build a castle and you want to add additional blocks, it will count toward the item count for the area. So if you didn't want to have any decorations inside of the castle, you could use 500 blocks in an area.
You can also purchase a Bric-a-Brac elixir to increase the item capacity by 50.