2015 aygo NSF susp arm replacement

[Black9]

My aygo was in for its mot yesterday at farmers auto care.. it failed on,

Nearside Front Suspension arm pin or bush excessively worn lower wishbone rear bush 

the mileage is only 30k, 1 owner, carefully driven - no previous advisories  

I’ve got the car booked in to be fixed and they are pushing for a wheel alignment after they arm replacement. Is this necessary? 

The steering wheel is currently slightly off centre but doesn’t bother me as roads here are so bad.. also is it likely a bush should wear this quick?

[flash22]

oh yes get it aligned, incorrect alignment will scrub a tyre in under 1000 miles, the wheel being off centre will also affect the indicators and more importantly the SAS (Steering angle sensor) EPS and ABS systems as well as the SRS

[Black9]

Are the rear adjustable at all on the aygo? Is it worth going four wheel setup or basic front wheel alignment? 
 

How many miles should I do before having it done and will it be an issue as only one arm was changed? 
 

Farmers offer front wheel alignment for £29 with a 29 day warranty