Yorke Peninsula Coach Services provide a service to Clare and the towns in the Clare Valley.
On Mondays, it doesn't operate, the rest of the week it does.
Please check the website for an up to date time-table of this service.
You would be looking at in 2012.... Adults...$36.00
I haven't used this service, but I loacted it and thought it may be good for people who wanted to take in a day trip to the Clare Valley.
This tour service will pick you up from your hotel and then take you to the Clare Valley. You can organise the tour to suit your needs/interests.
Please refer to their website for more details on this (and many other) tours.