In theory you can indeed set one computer up as a "host" and bridge the connections (Ad-Hoc Connection as I recall)
In practice. I've never been able to do it.
HOWEVER there is hope.. I am sitting here watching a REPLAYTV, which is connected to the internet, In the back of the RV is a 2nd REPLAY, and a Server that has to do with the REplay.. all are connected to the internet.. More later on what they do with the net.
I'm typing on a Laptop and anotehr net to me is crusing Publisher's clearing house
My phone is internet connected as is my tablet and a wireless printer.
ALL VIA ONE WI-FI ADAPTER One "ANTENNA" if you like.
Two ways to do it,, Since I've been doing it a long time I do it the "hard way" which I wont' describe because today there are easier ways.
Wi Fi Ranger.. This is a 2 part system... the "Antenna" goes outside the RV, up a pole on the roof, wherever it needs to be to get a clear shot at the router, You can even mount it in place of the feed horn on a Sat Antenna dish and with proper aiming ... Well, I have no idea what the range will be.
www.amateurlogic.tv Current episode (Today is 10/25/2016,,, the episode was released last week I think) shows how it's done.
Episode 3 shows how they built the can-tenna
The "indoor" unit is a wi-fi Router so you can connect multiple devices.
Also in the RV, I have a 2nd path to the park's Wi-Fi.
A TP link TL-MR3040 "repeater"/many function device
This device can act as a one piece repeater, letting me make one connection to the park but many connections to its internal router..
OR: it can take a USB stick be it cellular or Wi-Fi
OR, it can take a cat 5 Feed from another device
Or it can FEED another device via Cat5
It is currently in repeater mode, only thing plugged in is the power cord. I sometimes use it when my primary path is acting wonky (It's old and showing it's age)
The Replays (i promised more) Originally they got their program guides from the Internet, set the clock and a few other thigns, Alas DirecTV bought ReplayTV and promptly killed it off, they wanted the award winning interface for theire DVR's (Dish DVR's are based on the Replay by the way) so they bought it. Orignal Direc was based on TiVo
Today the Replays only look to the internet for the Time setting. Everythign else they get from the Server computer here in the motor home.. IT gets the program guides from the internet and if a software update is needed I get than and manually iniatite the update.
I can also use the local net to program the devices to record shows and such, download programming to the server and then to any device in the hosue, All sorts of thigns. But they don't do Wi-Fi.