FreshTomato does support VLAN setups and the user can create up to 16 VLANs. Any VLAN can use a VID between 1 to 4094.
Wireless - Assignments of wireless interfaces to different LAN briges. You should probably be using and/or check things on Advanced/Virtual Wireless and Basic/Network.
Other relevant notes/hints:
Configuration example for German Telekom ISP
Europe's biggest telecommunications company supports a dual-stack setup (IPv4 & IPv6) and for the WAN Port you need a VLAN tag with the value of 7 (VID 7).
IMPORTANT NOTE: please use FreshTomato 2021.8 and newer to have VLAN working properly.
All “older” versions (including shibby/toastman/AdvancedTomato/etc.) may not work like expected. PPPoE connection is only possible with the following “workaround”.
Example 1: If you are using FT 2021.7 to connect to German Telekom ISP (needs PPPoE with VID 7) ⇒ you have to use VLAN 7 using VID 7 (“traditional” VLAN/VID mapping)
Example 2: If you are using FT 2021.7 to connect to Freedom internet (https://freedom.nl needs PPPoE, only possible with VLAN 6 using VID 6) see https://www.linksysinfo.org/index.php?threads/fork-freshtomato-arm-development-discussion-only-for-support-always-open-your-own-thread.74117/page-245#post-330148
Example 3: If you are using FT 2021.7 to connect to Vivo FTTH (Brazil) (needs PPPoE, only possible with VLAN 10 using VID 10) see https://www.linksysinfo.org/index.php?threads/fresh-tomato-r7000-vlan-issue-on-ftth-provider.76958/#post-330955
Starting with release 2021.8, you can select or use any VLAN 0 to 15 (see picture above for example 1 (Telekom ISP), now using VLAN 5 with VID 7)