In a tweet on Aug 30th, Google announced they will be rolling out sitelinks at the account level. That means you would be able to set account-level sitelinks and won’t have to manually add them for each campaign. May save you a bit of work, though in some cases you would be better off customizing sitelinks for each campaign (depending on your account structure).
I checked several of the accounts we manage and don’t yet see this option in any account so most likely they will be rolling it out in the near future.
In reply to a question, they do mention they will be rolling this out for advertisers globally!