Well, first of all, it really depends on the SA and manager at your store when it comes to these kind of issues... I'm lucky cuz I'm a regular customer at my local boutique and know every SA so I had no problems getting a new one. Alternatively, they may offer you a free repair which involves sending the bag into repair and having them place a new front pocket onto the bag. However, this is a lengthy process which may take months and is nerve wrecking. Also, it could be that they'll make you pay for repair because LV only has a 2-year warantee time for manufacturing defects...
Secondly, LV is (or should be) fully aware of this particular problem. Like I said, the glue they used on their white MC bags between 2003-2005-ish reacted badly with the red alcantara interior lining, causing it to bleed through the white canvas. (on a side note: it is extremely obvious on Kim Kardashian's white mc keepall in the Celebrity Section thread). This is why they decided to discontinue the white MC mini HL bag because the bag would turn yellow with time.
Ok, to conclude, keep cool and calmly explain the above to your SA. You may be lucky and come out with a brand new mc speedy! Good luck!