On page 8 of the VW Sharan Pricelist (which contains the ‘specs’) it shows that SE NAV and above have:
‘Driver’s seat with electrically adjustable backrest and lumbar support’
https://www.volkswagen.co.uk/files/live/sites/vwuk/files/pdf/Brochures/sharan-pricelist.pdf
I would hazard a guess that ‘Electrically adjustable backrest’ = reclining seat
However, do check with your dealer and do try to get it in writing if it is very important to you. Also keep a copy of the specs of the car ‘as ordered’ and make sure, before you enter your PIN on collection day, that the specs are exactly ‘as ordered’. If not, do not enter your PIN and reject the car.
Dave