Yes. Nectar hosts its data with Amazon Web Services and force.com, two of the largest ecommerce and cloud computing companies in the world.
We also encrypt all personal and sensitive data.
We use Credit Sense (a highly secure Australian Credit Reporting Body) to access your bank information. Neither Nectar or Credit Sense keeps your internet banking credentials. Your credentials are encrypted when you enter them, passed to your bank to gain access to your transaction history and then permanently deleted.