So I am at company X, and my company has servers lets call them serverA.companyX.com for example
How does 10.0.8.1 as your home DNS know about serverA.companyX.com when it is only resolvable by computers on the companyX network - its is not open to the public NET.. For example the Active Directory servers.
While you can hand out multiple dns to your pfsense clients, just because you have multiple dns, depending on what the dns returns when asked for serverA.companyX.com its just going to stop.. And if I ask say the companyX dns for something at home pfsense.localdomain.net - it sure and the hell does not know..
The best solution to this sort of problem is say run bind on your box.. Point to it for dns.. And in it have forwarder for localdomain.net to ask your dns on your home network, and everything else go to your corp dns.
That way you can resolve both your company stuff and your home stuff when you have a vpn connection. It does not have to be bind, could be dnsmasq, tinydns, unbound, anything that can make the call..