Lending Tree is not a mortgage specialist, it is a mechanism to farm out your information to lenders, who all pull your credit. Those lenders sell and resell your information, all those lenders check your credit, and your credit score can take a big hit. I had a client that had this go on for over 6 months before she finally got it stopped. Maybe LT has changed the way they do business, but I doubt it. Most of these internet source lenders have to generate revenue and charge big loan origination fees to keep the lights on. I had a person get a quote from IFreedomDirect and the closing costs were thousands more than he could get from a local lender with the same interest rate.
And internet lenders are very impersonal, they do not care if they miss your closing date, the docs do not show up on time, the docs are wrong, whatever, they are a thousand miles away, so they do not care if you are happy or not. The chances of Rick G answering the phone at BigMortgageMart 6 months from now is about zero. Local lenders do care, they want your referral business, they want you to be happy.
So, the short answer is no, it does not matter, you can get pre-qualified anywhere without obligation. The long answers is yes, it matters, and be careful about where you send your personal information. So many people get caught up in looking at only interest rate, which is important, but do not look at the total package, closing costs, points, pre-payment penalty, etc., etc.. These things can cost you THOUSANDS.