By Devayani Sathyan BENGALURU (Reuters) - Australia's home prices will rise around 5-6% over the next two years as lower borrowing costs provide a fillip to home sales, although affordability pressures may cap gains, according to a Reuters poll of property analysts. While a 5% rise pales in comparison with past booms, any sustained growth in house prices will make it harder for first-time buyers to get a foothold in Australia's already expensive housing market - the median home price is nearly eight time ...