From the Anniversary rulebook, page 31:
“A transport can load and offload units without moving from the friendly sea zone it is in (this is known as “bridging”). Each such transport is still limited to its cargo capacity. It can offload in only one territory, and once it offloads, it cannot move, load, or offload again that turn”.
So it can bridge exactly one time per turn, either during Combat Move Phase (into a hostile territory) or during Noncombat Move Phase (into a friendly territory).