Mrs. Ciz & queenofthehive have given good info. The most recent bulk deposit of Wyndham resorts into RCI earlier this month was for check-ins in April 2019. So make sure there's an OGS (OnGoing Search) request in RCI, ready to match before the July deposits are made. RCI matches deposited weeks to the OGS wait list, first come, first served. So the earlier the OGS is entered, the better your chance of a match. Based on past patterns, Wyndham may deposit July 2019 Bonnet Creek weeks anytime between November 2018 and February 2019 - 5 to 8 months ahead of check-in. There will usually only be one bulk deposit made for a given month of check-ins and nearly all popular check-in deposits will be snapped up within a few days, especially for school vacation/break periods.
Note that some resorts, like DVC, place a block through RCI, preventing owners at other area resorts from exchanging in. So a Vistana owner may not exchange into DVC's SSR. So far, Wyndham has not instituted this kind of regional block.
Also, Wyndham can only use available inventory which has not been reserved by owners for their own vacations, to deposit weeks into RCI. So you generally won't see prime time, holiday weeks deposited to RCI, like July 4th, or very rarely. Owners book these pretty quickly. Same issue as when trying to trade into any resort system that does bulk deposits to RCI. Their prime holiday weeks, their largest units, and their most popular resorts get booked solid by owners. Ex., you won't see summer weeks deposited to RCI from Wyndham Old Town (Wash, DC) or Disney Grand Californian or HGVC/Hilton NYC or WorldMark Yellowstone in RCI. Nothing.
Wow, locked in with no changing. I don't even think DVC does that.
This references RCI exchanges and it applies to all of them, including DVC properties on exchange. The RCI exchange fee is non-refundable if you change or cancel after a day or so. However, when using owner points to reserve directly through the parent company (Wyndham, Hilton, DVC, etc.), it's different. We are Wyndham owners and we are able to make a certain number (based on # of points owned) of transactions/reservations per year without added fees. We haven't paid more than 1 or 2 transaction fees in 20 years. HTH.