No, I don't think pinning would work over BitLocker. BitLocker performs volume-level encryption, not whole drive. Pinning works by reading directly from the disk and parsing the various data structures GPT / MBR, partitions, file system. The file system would be completely opaque on a BitLocker encrypted drive, so pinning wouldn't be able to make any sense of it.
It should be theoretically possible to make pinning work on a volume level, it's just not how it works right now.