I would use a project for each feature area, but the right answer for you also depends to some extent on how you have set up the revision management system for the website - if the features are spread across several repositories or revision control systems or projects within a single repository, you already have a natural collection of projects, and it would be confusing to use a different arrangement for defect tracking.
I reserve areas to distinguish between problems related to the same project for which fixes require different release paths, e.g. Documentation (which has a slightly lower burden to republish) vs Software (which requires a release build, test, and Q/A) vs Firmware (which requires someone burn some EPROMS), or which might have different groups of employees working on them (e.g. User Interface, Database, Business Logic, Interoperability).