I've never gotten in the middle on those situations. My contract is with the homeowner, NOT the insurance company. I bid the job to the homeowner, provide any and all written documentation, insurance certificate, etc. and collect from the homeowner. They can submit the receipt for reimbursement.
Let them deal with their insurance company. Many Ins. Co.s will find a way to 'deduct' for this or that and I don't need to go back 4 weeks later to try and collect my last $300-$400 from the homeowner because the insurance company didn't follow through.
Standard policy here in FL. will pay up to $500 for removal of a tree struck by lightning, but nothing for preventative measures or trees that die from other causes.