Visa Expiring soon, but i94 valid, planning trip

[damannetwork]

My h1b visa expires this end of sept. However, I got new i94 after extension of h1b which is valid until 2018.

I am planning a trip to Mexico mid of September. Will there be any issues while entering back into US from Mexico because visa validity left on passport is very limited?

Also, how can I get new date on my visa as per new i94.