Yes! Much clearer now. As I said earlier, what made me struggle with VLANs on MK for days was because a couple of lines I totally missed to read in the @pcunite configuration file. I missed an important step, in the same way as when you lost a piece of a gear and you don’t know why it doesn’t work since you don’t have a complete - or at least proper - knowledge of it and how it works.
Futhermore, I also found this sentence by @mkx rather was enlightening:
BTW, in this context forget about native VLANs on mikrotik, IMO native VLANs concept can make more confusion than it does good. Just go with “all VLANs are equal” thinking.
here in this post:
http://forum.mikrotik.com/t/trunking-native-vlan/151306/1
The concept of native VLANs used basically on other brands had led me astray even more, making me think that I fad failed to understand something else important about VLANs. 
Now, I have a better understanding about VLANs on Mikrotik devices. Of course it doesn’t mean that I have become a VLAN bad-ass overnight, since there are still plenty of things that aren’t complete clear to me. I’m still have some doubt about the bridge in setting up VLANs. it is basically about why I need to add BRIDGE1 as a tagged port in the bridge itself. I need to dive a bit deeper into this.
Last thing. I also read this in this post here: http://forum.mikrotik.com/t/how-to-create-most-basic-vlan/153816/11
→ if you plug in your PC in port ether5 you won’t obtain any IP, except if you manually set a VLAN-Tag (111 or 222)
What exactly mean, " …except if you manually set a VLAN-TAG." Can I set a vlan tag on my pc?
Anyway, I think that I can go ahead now, and set the switch device connected to the router (alway in my virtual environment) on the trunk port.
Thanks all for your advice