Did you have something in writing (a report at $2895 that was requiring tenting). If you did than you may be able to dispute this. If you don't have a report that states tenting is needed then I don't think there is much you can do. I am not a termite inspector but as a realtor and homeowner here are my two cents:
I have seen termites (evidence) on homes a couple weeks and months after tenting. I don't think tenting has much or any residual effect. The good news is some spot treatments (like Borate) is more Eco friendly and does have a residual effect. Also, I don't particularly care for the smell of the tenting. It stinks and if it's not needed in the report than you make not need it. The other thing you might want to do, is to see if there is any possibility of getting another company to get a person to inspect the attic that can fit in the small space.If they can't see it, they can't recommend it. No I personally would request a second inspection and also call the termite company and see why they recommend the "substandard recomendation". Perhaps the seller doesn't want the hassle of tenting. I think further investigation about this issue needs to be done. Call your agent and call the termite company.
The Carrabba Group
Keller Williams Wilshire
As I understand it::
Because it leaves no residue, sulfuryl fluoride (aka “Vikane”), which is commonly used for termite tenting, provides no protection from future infestations. Heavy reinfestation can take several years since drywood termites have slower growing colonies than ground termites. My understanding is that sulfuryl fluoride blocks the absorption of nutrients to the termite. It is common to see a temporary increase in ant activity after a tenting as they will go into the termite tunnels and "harvest" the prior occupants.