That is not really well supported.
You can sync your events and albums to your iPad using iTunes, but there is no good way to get your edits back to your mac.
if you have iPhoto on your iPad, you can edit your photos on your iPad, add captions and tag them.
You can share the edited pahoto to iTunes or your Camera Roll. This way you can reimport the photos, with the tags and edits. But the connection to the original photos, evens, and albums in your iPhoto Library will be lost. Syncing to your iPad s essentially one-way. There is no good way back to the Mac.
I know Mick. I wish it were different.
But I hope the future versions of the IOS apps will bring more functionality to the IOS apps. Right now they are more designed as end points for sharing via email, uploading to social media, etc.
When I go on vacation, I take my MBP with me for photo editing, not my iPad
If I now edit and organise my photos on the iPad is there no way of transferring those changes back to the iMac in iPhotos. Can I do it through an app like PhotoManager Pro?
As I said, you can send the edits back from iPhoto on your iPad, as well as from PhotoManager.
I have not tried PhotoManagerPro so far. The reviews are saying, it very good for organizing the Photos on your iPad, but it has the disadvantage, that it will copy all files that it stores - iPhoto will only link to the files in the Camera Roll and not require extra space.
I cannot find any indication, that Photo Manager will let you sync the albums back, only the photos. So it seems to have the same limitations as iPhoto.
Let's wait, if somebody drops in who has tried other apps.
I have been struggling with moving my iPad edits to my Mac for months and have finally figured a way to at least get that over to my Mac effectively. I went to Italy and loaded all my photos directly to my iPad and made edits on the plane home, but wanted to include them in my main iPhoto library on my computer.
If you go into the iPad iPhoto app, you can read about it in the help topics (it was actually useful for once!) by choosing the Share your photos> Use photos in other apps> and scroll down to the Import photos to iPhoto on your computer topic.
The gist is, open an album from the iPad, and use the export button. Choose iTunes, and it will queue the images. When you attach your iPad to your computer, go to the apps tab once iTunes opens and scroll to the bottom, where you should see an area on the right with your files ready to import. This link has the info from that point.
Because the iPhoto Library is a packaged folder you shouldn't mess with (corruption abounds, apparently), I opted to import the photos to a folder on my Mac, then used File>Import to Library on my Mac to get them in. Kinda multistep, but not too hard. Hope this helps!