Trying to configure a 2830n with two SSIDs. Each SSID will have different web access (firewall rules).

Is this possible? If it is, how are firewall rules matched to an SSID?

I don't think what it can be done dynamically.
The only way to match the Filter Polices would be to create the 2nd SSID on another VLAN and then use that as the source.

If you know exactly what the device's are then you could do it by MAC address also but it would need to be configured as a group and you would need to add the MAC for every additional device from then on.

Separate VLAN is the easiest approach I'd say

Thank you Sicon,

I can see we have two VLANs each has rules that control how users off site traffic (internet),
but within the site are VLANs visible to one another? ie if a printer exists on one VLAN, is it accessible from the other?

You can limit access between VLANs using the firewall (need to enable inter lan routing first then lock it down so only the printer can accessed) or put the printer in its own VLAN