VeraCrypt - Encryption of Host Protected Area on my Macbook Pro 13"
Download a decent but free partition tool for Windows like MiniTool Partition Wizard Free Edition 9 and check for a HFS+ volume at the end of the disk. The size is ~650 MB and the GUID type: 426F6F74-0000-11AA-AA11-00306543ECA.

If it doesn't exist anymore - after installing Windows - go ahead and encrypt the whole drive.

If it exists, try to boot to Internet Recovery Mode with cmdaltR to check if it works with your network setup. If you have been successful (you will see a little spinning globe and boot to a recovery screen), reboot to Windows and delete the Recovery HD-partition. Expand your Windows partition and encrypt the whole disk with VeraCrypt afterwards.
Using only Windows, the Mac Recovery HD partition on your disk device is almost useless.

Booted to Internet Recovery Mode you will always be able to reinstall a current Mac OS X given that you have a decent internet connection.