Hi Andy,
Strictly speaking, nearly all of that is available for the application to use. However, once you add various PSoC Components into the project schematic so that the IDE generates relevant API code for you, and particularly once you start using those APIs in your code, some flash and RAM will be used by the APIs and (in the case of BLE) pre-compiled object code that provides core BLE stack functionality.
The specific memory footprint depends on which APIs you end up using. For example, if you design a project with peripheral-only BLE capability, you will have more space available for the application than if you design peripheral and central together in the same project.
For a very rough ballpark, I would refer to the simple "BLE_Find_Me" example project that comes with PSoC Creator. This is a peripheral-only project with basic BLE functionality. Here's the compiler output:
Flash used: 83099 of 131072 bytes (63.4 %).
SRAM used: 11568 of 16384 bytes (70.6 %). Stack: 2048 bytes. Heap: 1024 bytes.
