VLAN-tagging - follow-up

Are you supposed to "bridge" the vlan with the physical interface?

I have:

$ cat /etc/hostname.em0
up

$ cat /etc/hostname.vlan101
vnetid 101 parent em0
inet autoconf
up

In /etc/pf.conf I have replaced em0 with vlan101 for ext_if.

I get "No route to host" if I try to ping something, etc.

But if add:

$ cat /etc/hostname.bridge0
add vlan101
add em0
up

Then it works.

Was the bridge part missed in the previous emails about how to use
VLAN-tagging or am I missing something?