I am connected to work over a PPPOE connection but to some systems I am required to have a L2TP tunnel.
I tried to follow the next tutorials:
http://wiki.mikrotik.com/wiki/Policy_Base_Routing
http://wiki.mikrotik.com/wiki/PBR_PTP_IPIP

In order to implement PBR for specific hosts on my network.
The first test was to verify if it's possible over the current router ie using ethernet1(on RB750Gr2+3) in DHCP and an L2TP over it with PBR.
The result was good but then I move to a full blown Mikrotik based PPPOE+L2TP+PBR.
Then I got to the state which the PPPOE was up and the L2TP was up and I could use the PPPOE connection.
When I moved on to turn on the PBR the traffic "Stopped" for this specific source address which I used in the PBR.
The technical support gave me a solution which was tod disable the "FastTrack" in the firewall filter table.
As soon it was disabled the connection started working great.

I do not know if it's a bug or not but since my connection is an ADSL which is way below 100Mbps it works fine.
For others with much higher speeds connections there would might be a slowdown in the router overall speed.

Thanks for the support team for the solution.