Correctly. What I want is access from LAN to ONT. Now, I can access to Internet through ONT with VLAN without problems.
I "redraw" scheme of my config in first post.
I have the following setup to access Internet:
FTTH <----> ONT Router <----> (WAN Port) RT-AC86U <----> LAN
Internet <---------------------> VLAN <----------------> LAN
Internet <---------------------> Public IP <-----------> 192.168.1.1/24
---------- 192.168.100.1/24...