To address your specific question: No, the Bolton result still matters.
As of today, 4/4, only four teams are left in the race to catch United: Bolton (magic number 13), Fleetwood (6), Bradford (3) and Scunthorpe (1). (Magic number = combination of points won by United, or lost by any other team. For example, Southend lost 3 by losing today.) With Southend's loss to Bolton, they are mathematically out of the race.
If United beats both Coventry and Northampton (gaining 6 points), and Bolton loses to Scunthorpe (losing 3), that in and of itself would not seal the title, since Bolton's magic number would be down to 4. That means United would have to either: (a) beat Port Vale on the 14th, and Bolton would have to either lose or draw to Oldham on the 15th, or (b) draw with Port Vale on the 14th, and Bolton lose to Oldham on the 15th.
Thus, United will need some help from Scunthorpe AND Oldham for the title to be sealed.
With respect to tomorrow's game, looking at United in isolation:
If United loses, the magic numbers are as above (13-6-3-1).
If United draws, Scunthorpe is out, Bolton goes to 12, Fleetwood 5, and Bradford 2 (ignoring the result of the Fleetwood match).
If United wins, Scunthorpe and Bradford are out, Bolton goes to 10, and Fleetwood 3 (again ignoring the Fleetwood match).
Looking at tomorrow's Fleetwood result as well:
If United wins and Fleetwood wins, still Bolton 10, Fleetwood 3.
If United wins and Fleetwood draws, Bolton at 10 and Fleetwood 1.
If United wins and Fleetwood loses, Bolton at 10, Fleetwood is out and United clinches automatic promotion (but not yet the title).
