Welcome to the Apple Community.
I'm assuming from your description that you are using iTunes match.
If there isn't a cloud next to an item on your phone, it's because it's already on your phone, the cloud icon indicates it's in the cloud and can be downloaded.
Tunes purchased on your phone will only download to your PC in one of two ways. Either you manually download it by clicking on the cloud icon next to that tune in iTunes or you have iTunes set to automatically download new purchases (preferences > store)
Thank you for your respons, much appreciated.
Sorry to sound thick but i thought with icloud when i purchase tunes from itunes on my phone then it would automaticlly appear on my pc. this is not the case. There is no icloud icon next to the tune for me to click on.
Yes anything you purchase on one device will automatically download to the other, provided your preferences are set to do that.
If there is no cloud icon next to a tune, that indicates it is already downloaded.