That varies by brand as far as the warranty contract, but as a practical matter a dealer for xyz brand can get reimbursed for warranty work on any xyz tractor, so he will generally do the warranty work as it is good business (although generally not profitable) to do so. But if a dealer is really busy, a customer that bought from him will generally get his work done before a customer that did not. And a dealer will sometimes "goodwill" a minor problem that isn't actually covered under warranty at his own expense for a good customer. So there are advantages to going back to your selling dealer.
We will do Mahindra warranty work on any Mahindra as long as it was legally purchased/owned and registered, etc. To do otherwise just looks like sour grapes and never ends well. The exception is if a local guy runs over the state line to avoid sales tax and then brings it to us for warranty, we do require that he show us proof of paying "use tax". If so, we are on it, if not he evaded tax, not avoided tax and we won't touch the tractor. We won't get sideways with the tax folks for any reason....they can make or break a small business and it isn't worth a little bit of warranty reimbursement income. But I think I have opened up another subject, and we probably should not get off track.