Marriage at 19 would not be particularly unusual in that area at the time, but if you are looking at the baptism 19 February 1726, that is actually February 1726/1727 as can be seen from the register, the new year began 25 March at that time for register purposes. The baptism was at Beeston chapel and also recorded at the main church.
https://www.ancestry.co.uk/discoveryui-content/view/9078789:2256
John Bentley is quite a common name and there is also a John Bentley son of John baptised 11 April 1720 at Holbeck, the adjoining township to Hunslet
https://www.ancestry.co.uk/discoveryui-content/view/10275339:2256
There may be more John Bentleys either at the main church or the chapelries. The Leeds chapelry registers are partially published from about 1720 onwards and on the Internet Archive, They show a marriage at Beeston 19 October 1721 of John Bentley and Ann Wilson, who may be the parents of John 1726/1727, but there are other children both of Beeston and Holbeck, who appear to be two separate families.
https://archive.org/details/pt1publications23thor/page/2/mode/2up
If you sort the children out into the two families it might help to find the correct marriage dates. (The main register would need to be checked for children and marriages too).