There's nothing quite on the doorstep, but cast your net around 4 or 5 miles from the glamping site and there are heaps of options. 

The nearest pub is The Severn Bore, which serves traditional pub food.  It is approximately a 15 minute walk or if you take the more scenic route along the river, approximately 25 minutes.  

Then there is The Lyon Inn in Westbury on Severn approximately 3 miles away and The Red Hart in Blaisdon, approximately 5 miles away.

Or why not try the The Severn & Wye Smokery Restaurant in Westbury on Severn (just over 1 mile away).  This is a Michelin starred restaurant. 

Finally, for general supplies, Chaxhill Garage is a Londis garage/shop, just over a mile away.