BRIDGE public + local interfaces !!!!!

i just made a bridge between public and Local interfaces thats only to give a public IP to 2nd MT connected to local interface ..

i found that i have two ways to give public ip first is by maping (1:1 NAT ) second is by bridging public+LOCAL ..

i just wanna know whts the advantage and disadvantages of using this BRIDGE

is it very simple , hard or silly question ?
anyway
its working ok , but i just want to know why somebody advice not to bridge the public + local interface ?
** i have 4 interfaces at the main MT , 1 for wan , 1 for local clients , and the 3rd is connected to a remote MT which i gave a public IP ..
** i have /28 public subnet
its working , but i cant get in the remote MT using winbox !!! after login in winbox it gave me a message .. that IP couls not response !!!

i just wanna put a PUBLIC IP on the remote MT without natting , is it correct or wrong and why ???

is it invisible ??

you dont need a router for bridge or layer 2 network