If I use two waps in transparent bridge mode to connect two buildings
and at each end I have switches that are 802.1x, vlan and qos capable do
the waps need to understand 802.1x, vlan & qos or are they truly
transparent as though they were just a cable connecting the two
switches?

These are the bridges I am looking at:-

Repeatit SU-2410b/g Outdoor 802.11b/g Bridge Kit

http://www.wifigear.co.uk//images/So...iber+units.pdf