Taxonomy on each field value
Create a multi-value Field Group, with one taxonomy term reference (tag), and one image. Field group values can be used in views via Field group views module.

Alternatively you can do the same using Field collection module - younger, without 6.x roots, written to utilize entity api (and it means native views integration).

For bulk uploading, there is Field Collection Bulkupload, it seems to work, if with issues (as to be expected for alpha module). If you need bulk upload capabilities and equivalent of collections, joining efforts with it's team should be your best bet.