Can still boot to Windows even though I deleted the partition I re-installed Mac OS and erased the recovery partition so Bootcamp would have a punt at installing Windows.

Still not managed to re-install Windows, and when I boot with -Alt- held down it still shows Windows as a disk. Why is it still there?
First of all the Recovery partition has nothing to do with BootCamp. BootCamp installs a small Windows boot partition that then points to the (separate) Windows partition where the rest of the installation is, if I recall correctly.

When you hold down the Option key at boot (it's only called "ALT" on Windows) the Mac only sees the small boot partition not the second one with the Windows installation on it.

I would be willing to bet that if you selected to boot from Windows from the boot menu you would get an error about *no bootable disk found" or some such.

In the case of BootCamp it is best to not do anything outside the BootCamp installer environment unless you have a bit of experience with it and know just how the partition map is set up. Apple likes to insulate users from the innards of the OS so you rarely see the whole story.

Just like you won't know how to remodel an 1890s Victorian by watching This Old House, watching what the BootCamp application seems to do won't tell you the whole story.