Oh, i use no partition, this screenshot , setting for disk-utility is better.
The SparseBundle is expanding and only needs the space which is filled, with a tiny bit of overhead. It means if you have a 64GB Bundle, and store 10GB in it it will use 12GB or so on disk. You cannot resize a SparseBundle later, so choose it big enough. But it's possible to create a bigger Sparsebundle and just copy the contents.