https://www.manageengine.com/products/mibbrowser-free-tool/
Q-BRIDGE-MIB refers only to internal VLAN indexes,
you need to use both MIBs to get Port/VLAN mappings including the 802.1Q VLAN tag ID (jnxExVlanTag).
{master:0}
readonly@EX4300-Client-1-Active> show snmp mib walk 1.3.6.1.2.1.17.1.4
dot1dBasePort.4096 = 4096
dot1dBasePort.4097 = 4097
dot1dBasePortIfIndex.4096 = 513
dot1dBasePortIfIndex.4097 = 514
dot1dBasePortCircuit.4096 = 0.0
dot1dBasePortCircuit.4097 = 0.0
dot1dBasePortDelayExceededDiscards.4096 = 0
dot1dBasePortDelayExceededDiscards.4097 = 0
dot1dBasePortMtuExceededDiscards.4096 = 0
dot1dBasePortMtuExceededDiscards.4097 = 0