bridgeing multiple ports in the same vlan is simple.
You assign the various access ports to the same vlan
on the SRX240 you add l3 interface to the vlan and create the vlan interface (also called the RVI)
on the SRX300 series the process changes to using IRB interfaces
But bridge domains where multiple different vlan tags are bridged tot he same broadcast domain is only supported on the MX.